diff --git a/lib/pg_ha_migrations/safe_statements.rb b/lib/pg_ha_migrations/safe_statements.rb
index 73df8cf..29101dd 100644
--- a/lib/pg_ha_migrations/safe_statements.rb
+++ b/lib/pg_ha_migrations/safe_statements.rb
@@ -74,7 +74,7 @@ def safe_add_column(table, column, type, options = {})
   end
 
   def unsafe_add_column(table, column, type, options = {})
-    safely_acquire_lock_for_table(table) do
+    safely_acquire_lock_for_table(table, mode: :access_exclusive) do
       super(table, column, type, **options)
     end
   end
@@ -137,19 +137,19 @@ def safe_change_column_default(table_name, column_name, default_value)
       ERROR
     end
 
-    safely_acquire_lock_for_table(table_name) do
+    safely_acquire_lock_for_table(table_name, mode: :access_exclusive) do
       unsafe_change_column_default(table_name, column_name, default_value)
     end
   end
 
   def safe_make_column_nullable(table, column)
-    safely_acquire_lock_for_table(table) do
+    safely_acquire_lock_for_table(table, mode: :access_exclusive) do
       unsafe_execute "ALTER TABLE #{table} ALTER COLUMN #{column} DROP NOT NULL"
     end
   end
 
   def unsafe_make_column_not_nullable(table, column, options={}) # options arg is only present for backwards compatiblity
-    safely_acquire_lock_for_table(table) do
+    safely_acquire_lock_for_table(table, mode: :access_exclusive) do
       unsafe_execute "ALTER TABLE #{table} ALTER COLUMN #{column} SET NOT NULL"
     end
   end
@@ -204,8 +204,7 @@ def safe_add_concurrent_partitioned_index(
       PgHaMigrations::Index.from_table_and_columns(child_table, columns)
     end
 
-    # TODO: take out ShareLock after issue #39 is implemented
-    safely_acquire_lock_for_table(parent_table.fully_qualified_name) do
+    safely_acquire_lock_for_table(parent_table.fully_qualified_name, mode: :share) do
       # CREATE INDEX ON ONLY parent_table
       unsafe_add_index(
         parent_table.fully_qualified_name,
@@ -235,7 +234,7 @@ def safe_add_concurrent_partitioned_index(
 
     # Avoid taking out an unnecessary lock if there are no child tables to attach
     if child_indexes.present?
-      safely_acquire_lock_for_table(parent_table.fully_qualified_name) do
+      safely_acquire_lock_for_table(parent_table.fully_qualified_name, mode: :access_exclusive) do
         child_indexes.each do |child_index|
           say_with_time "Attaching index #{child_index.inspect} to #{parent_index.inspect}" do
             connection.execute(<<~SQL)
@@ -279,7 +278,7 @@ def safe_rename_constraint(table, from:, to:)
     quoted_constraint_to_name = connection.quote_table_name(to)
     sql = "ALTER TABLE #{quoted_table_name} RENAME CONSTRAINT #{quoted_constraint_from_name} TO #{quoted_constraint_to_name}"
 
-    safely_acquire_lock_for_table(table) do
+    safely_acquire_lock_for_table(table, mode: :access_exclusive) do
       say_with_time "rename_constraint(#{table.inspect}, from: #{from.inspect}, to: #{to.inspect})" do
         connection.execute(sql)
       end
@@ -293,7 +292,7 @@ def unsafe_remove_constraint(table, name:)
     quoted_constraint_name = connection.quote_table_name(name)
     sql = "ALTER TABLE #{quoted_table_name} DROP CONSTRAINT #{quoted_constraint_name}"
 
-    safely_acquire_lock_for_table(table) do
+    safely_acquire_lock_for_table(table, mode: :access_exclusive) do
       say_with_time "remove_constraint(#{table.inspect}, name: #{name.inspect})" do
         connection.execute(sql)
       end
diff --git a/spec/safe_statements_spec.rb b/spec/safe_statements_spec.rb
index 18dcd57..73e64a9 100644
--- a/spec/safe_statements_spec.rb
+++ b/spec/safe_statements_spec.rb
@@ -618,7 +618,7 @@ def up
           it "calls safely_acquire_lock_for_table" do
             migration = Class.new(migration_klass).new
 
-            expect(migration).to receive(:safely_acquire_lock_for_table).with(:foos)
+            expect(migration).to receive(:safely_acquire_lock_for_table).with(:foos, mode: :access_exclusive)
             migration.unsafe_add_column(:foos, :bar, :text)
           end
         end
@@ -796,7 +796,7 @@ def up
 
             migration = Class.new(migration_klass).new
 
-            expect(migration).to receive(:safely_acquire_lock_for_table).with(:foos)
+            expect(migration).to receive(:safely_acquire_lock_for_table).with(:foos, mode: :access_exclusive)
             migration.safe_change_column_default(:foos, :bar, 5)
           end
 
@@ -1081,7 +1081,7 @@ def up
           it "calls safely_acquire_lock_for_table" do
             migration = Class.new(migration_klass).new
 
-            expect(migration).to receive(:safely_acquire_lock_for_table).with(:foos)
+            expect(migration).to receive(:safely_acquire_lock_for_table).with(:foos, mode: :access_exclusive)
             migration.safe_make_column_nullable(:foos, :bar)
           end
         end
@@ -1251,7 +1251,7 @@ def up
           it "calls safely_acquire_lock_for_table" do
             migration = Class.new(migration_klass).new
 
-            expect(migration).to receive(:safely_acquire_lock_for_table).with(:foos)
+            expect(migration).to receive(:safely_acquire_lock_for_table).with(:foos, mode: :access_exclusive)
             migration.unsafe_make_column_not_nullable(:foos, :bar, :estimated_rows => 0)
           end
         end
@@ -1302,8 +1302,10 @@ def up
             allow(ActiveRecord::Base.connection).to receive(:execute).and_call_original
 
             aggregate_failures do
-              expect(ActiveRecord::Base.connection).to receive(:execute).with(/CREATE INDEX "index_foos3_on_updated_at" ON ONLY/).once
+              expect(ActiveRecord::Base.connection).to receive(:execute).with(/LOCK "public"."foos3" IN SHARE MODE/).once.ordered
+              expect(ActiveRecord::Base.connection).to receive(:execute).with(/CREATE INDEX "index_foos3_on_updated_at" ON ONLY/).once.ordered
               expect(ActiveRecord::Base.connection).to_not receive(:execute).with(/CREATE INDEX CONCURRENTLY/)
+              expect(ActiveRecord::Base.connection).to_not receive(:execute).with(/LOCK "public"."foos3" IN ACCESS EXCLUSIVE MODE/)
               expect(ActiveRecord::Base.connection).to_not receive(:execute).with(/ALTER INDEX .+\nATTACH PARTITION/)
             end
 
@@ -1332,8 +1334,10 @@ def up
             allow(ActiveRecord::Base.connection).to receive(:execute).and_call_original
 
             aggregate_failures do
+              expect(ActiveRecord::Base.connection).to receive(:execute).with(/LOCK "public"."foos3" IN SHARE MODE/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/CREATE INDEX "foos3_idx" ON ONLY/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/CREATE INDEX CONCURRENTLY/).exactly(10).times.ordered
+              expect(ActiveRecord::Base.connection).to receive(:execute).with(/LOCK "public"."foos3" IN ACCESS EXCLUSIVE MODE/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/ALTER INDEX .+\nATTACH PARTITION/).exactly(10).times.ordered
             end
 
@@ -1371,8 +1375,10 @@ def up
             allow(ActiveRecord::Base.connection).to receive(:execute).and_call_original
 
             aggregate_failures do
+              expect(ActiveRecord::Base.connection).to receive(:execute).with(/LOCK "public"."foos3" IN SHARE MODE/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/CREATE INDEX "index_foos3_on_updated_at" ON ONLY/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/CREATE INDEX CONCURRENTLY/).exactly(10).times.ordered
+              expect(ActiveRecord::Base.connection).to receive(:execute).with(/LOCK "public"."foos3" IN ACCESS EXCLUSIVE MODE/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/ALTER INDEX .+\nATTACH PARTITION/).exactly(10).times.ordered
             end
 
@@ -1406,8 +1412,10 @@ def up
             allow(ActiveRecord::Base.connection).to receive(:execute).and_call_original
 
             aggregate_failures do
+              expect(ActiveRecord::Base.connection).to receive(:execute).with(/LOCK "public"."foos3" IN SHARE MODE/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/CREATE UNIQUE INDEX "index_foos3_on_created_at_and_updated_at" ON ONLY/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/CREATE UNIQUE INDEX CONCURRENTLY/).exactly(10).times.ordered
+              expect(ActiveRecord::Base.connection).to receive(:execute).with(/LOCK "public"."foos3" IN ACCESS EXCLUSIVE MODE/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/ALTER INDEX .+\nATTACH PARTITION/).exactly(10).times.ordered
             end
 
@@ -1442,8 +1450,10 @@ def up
             allow(ActiveRecord::Base.connection).to receive(:execute).and_call_original
 
             aggregate_failures do
+              expect(ActiveRecord::Base.connection).to receive(:execute).with(/LOCK "public"."foos3" IN SHARE MODE/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/CREATE INDEX "index_foos3_on_updated_at" ON ONLY/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/CREATE INDEX CONCURRENTLY/).exactly(10).times.ordered
+              expect(ActiveRecord::Base.connection).to receive(:execute).with(/LOCK "public"."foos3" IN ACCESS EXCLUSIVE MODE/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/ALTER INDEX .+\nATTACH PARTITION/).exactly(10).times.ordered
             end
 
@@ -1478,8 +1488,10 @@ def up
             allow(ActiveRecord::Base.connection).to receive(:execute).and_call_original
 
             aggregate_failures do
+              expect(ActiveRecord::Base.connection).to receive(:execute).with(/LOCK "public"."foos3" IN SHARE MODE/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/CREATE INDEX "index_foos3_on_lower_text_column" ON ONLY/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/CREATE INDEX CONCURRENTLY/).exactly(10).times.ordered
+              expect(ActiveRecord::Base.connection).to receive(:execute).with(/LOCK "public"."foos3" IN ACCESS EXCLUSIVE MODE/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/ALTER INDEX .+\nATTACH PARTITION/).exactly(10).times.ordered
             end
 
@@ -1521,8 +1533,10 @@ def up
             allow(ActiveRecord::Base.connection).to receive(:execute).and_call_original
 
             aggregate_failures do
+              expect(ActiveRecord::Base.connection).to_not receive(:execute).with(/LOCK "public"."foos3" IN SHARE MODE/)
               expect(ActiveRecord::Base.connection).to_not receive(:execute).with(/CREATE INDEX IF NOT EXISTS "index_foos3_on_updated_at" ON ONLY/)
               expect(ActiveRecord::Base.connection).to_not receive(:execute).with(/CREATE INDEX CONCURRENTLY IF NOT EXISTS/)
+              expect(ActiveRecord::Base.connection).to_not receive(:execute).with(/LOCK "public"."foos3" IN ACCESS EXCLUSIVE MODE/)
               expect(ActiveRecord::Base.connection).to_not receive(:execute).with(/ALTER INDEX .+\nATTACH PARTITION/)
             end
 
@@ -1555,8 +1569,10 @@ def up
             allow(ActiveRecord::Base.connection).to receive(:execute).and_call_original
 
             aggregate_failures do
+              expect(ActiveRecord::Base.connection).to receive(:execute).with(/LOCK "public"."foos3" IN SHARE MODE/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/CREATE INDEX IF NOT EXISTS "index_foos3_on_updated_at" ON ONLY/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/CREATE INDEX CONCURRENTLY IF NOT EXISTS/).exactly(10).times.ordered
+              expect(ActiveRecord::Base.connection).to receive(:execute).with(/LOCK "public"."foos3" IN ACCESS EXCLUSIVE MODE/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/ALTER INDEX .+\nATTACH PARTITION/).exactly(10).times.ordered
             end
 
@@ -1588,8 +1604,10 @@ def up
             allow(ActiveRecord::Base.connection).to receive(:execute).and_call_original
 
             aggregate_failures do
+              expect(ActiveRecord::Base.connection).to receive(:execute).with(/LOCK "public"."foos3'" IN SHARE MODE/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/CREATE INDEX "foos3'_bar""_idx" ON ONLY/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/CREATE INDEX CONCURRENTLY "index_foos3'_child_on_updated_at" ON/).once.ordered
+              expect(ActiveRecord::Base.connection).to receive(:execute).with(/LOCK "public"."foos3'" IN ACCESS EXCLUSIVE MODE/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/ALTER INDEX .+\nATTACH PARTITION/).once.ordered
             end
 
@@ -1634,8 +1652,10 @@ def up
             allow(ActiveRecord::Base.connection).to receive(:execute).and_call_original
 
             aggregate_failures do
+              expect(ActiveRecord::Base.connection).to receive(:execute).with(/LOCK "partman"."foos3" IN SHARE MODE/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/CREATE INDEX "index_foos3_on_updated_at" ON ONLY/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/CREATE INDEX CONCURRENTLY/).exactly(10).times.ordered
+              expect(ActiveRecord::Base.connection).to receive(:execute).with(/LOCK "partman"."foos3" IN ACCESS EXCLUSIVE MODE/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/ALTER INDEX .+\nATTACH PARTITION/).exactly(10).times.ordered
             end
 
@@ -1680,8 +1700,10 @@ def up
             allow(ActiveRecord::Base.connection).to receive(:execute).and_call_original
 
             aggregate_failures do
+              expect(ActiveRecord::Base.connection).to receive(:execute).with(/LOCK "public"."foos3" IN SHARE MODE/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/CREATE INDEX "index_foos3_on_updated_at" ON ONLY/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/CREATE INDEX CONCURRENTLY/).once.ordered
+              expect(ActiveRecord::Base.connection).to receive(:execute).with(/LOCK "public"."foos3" IN ACCESS EXCLUSIVE MODE/).once.ordered
               expect(ActiveRecord::Base.connection).to receive(:execute).with(/ALTER INDEX .+\nATTACH PARTITION/).once.ordered
             end
 
@@ -2194,7 +2216,7 @@ def up
           it "calls safely_acquire_lock_for_table" do
             migration = Class.new(migration_klass).new
 
-            expect(migration).to receive(:safely_acquire_lock_for_table).with(:foos)
+            expect(migration).to receive(:safely_acquire_lock_for_table).with(:foos, mode: :access_exclusive)
             migration.safe_rename_constraint(:foos, :from => :constraint_foo_bar_is_not_null, :to => :other_constraint)
           end
         end
@@ -2214,7 +2236,7 @@ def up
           it "calls safely_acquire_lock_for_table" do
             migration = Class.new(migration_klass).new
 
-            expect(migration).to receive(:safely_acquire_lock_for_table).with(:foos)
+            expect(migration).to receive(:safely_acquire_lock_for_table).with(:foos, mode: :access_exclusive)
             migration.unsafe_remove_constraint(:foos, :name => :constraint_foo_bar_is_not_null)
           end