diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4eb55e94..f28e901c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -32,6 +32,13 @@ option(freetype-gl_BUILD_HARFBUZZ "Build the freetype-gl harfbuzz support (exper
 option(freetype-gl_BUILD_MAKEFONT "Build the makefont tool" ON)
 option(freetype-gl_BUILD_TESTS "Build the tests" ON)
 
+if(${freetype-gl_BUILD_TESTS})
+    find_package(ImageMagick QUIET COMPONENTS compare)
+    if(NOT ${ImageMagick_EXECUTABLE_DIR})
+        message(FATAL_ERROR "ImageMagick was not found. Either provide path to ImageMagick, or disable freetype-gl_BUILD_TESTS option.")
+    endif()
+endif()
+
 include(RequireIncludeFile)
 include(RequireFunctionExists)
 include(CheckLibraryExists)
@@ -63,11 +70,10 @@ check_symbol_exists(M_PI math.h HAVE_M_PI)
 
 if(NOT HAVE_M_PI)
     list(APPEND CMAKE_REQUIRED_DEFINITIONS -D_USE_MATH_DEFINES)
-    unset(HAVE_M_PI CACHE)
 
-    check_symbol_exists(M_PI math.h HAVE_M_PI)
+    check_symbol_exists(M_PI math.h HAVE_M_PI2)
 
-    if(NOT HAVE_M_PI)
+    if(NOT HAVE_M_PI2)
         message(FATAL_ERROR "`M_PI` not defined in `math.h`.")
     else()
         add_definitions(-D_USE_MATH_DEFINES)
diff --git a/demos/CMakeLists.txt b/demos/CMakeLists.txt
index 5d55646c..f99460ee 100644
--- a/demos/CMakeLists.txt
+++ b/demos/CMakeLists.txt
@@ -54,27 +54,29 @@ target_include_directories(demo-utils
     PUBLIC $<TARGET_PROPERTY:glfw,INTERFACE_INCLUDE_DIRECTORIES>
 )
 
-add_custom_command(
-    DEPENDS
-        makefont
-        ${CMAKE_CURRENT_SOURCE_DIR}/CMakeLists.txt
-    COMMAND
-        ../$<$<BOOL:MSVC>:$(Configuration)/>makefont
-    ARGS
-        --font fonts/Vera.ttf
-        --header ${CMAKE_CURRENT_SOURCE_DIR}/vera-16.h
-        --size 16
-        --variable font
-    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
-    OUTPUT ${CMAKE_CURRENT_SOURCE_DIR}/vera-16.h
-)
+if(freetype-gl_BUILD_MAKEFONT)
+    add_custom_command(
+        DEPENDS
+            makefont
+            ${CMAKE_CURRENT_SOURCE_DIR}/CMakeLists.txt
+        COMMAND
+            ../$<$<BOOL:MSVC>:$(Configuration)/>makefont
+        ARGS
+            --font fonts/Vera.ttf
+            --header ${CMAKE_CURRENT_SOURCE_DIR}/vera-16.h
+            --size 16
+            --variable font
+        WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
+        OUTPUT ${CMAKE_CURRENT_SOURCE_DIR}/vera-16.h
+    )
 
-add_custom_target(generate-embedded-font
-    DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/vera-16.h
-)
+    add_custom_target(generate-embedded-font
+        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/vera-16.h
+    )
 
-create_demo(embedded-font embedded-font.c)
-add_dependencies(embedded-font generate-embedded-font)
+    create_demo(embedded-font embedded-font.c)
+    add_dependencies(embedded-font generate-embedded-font)
+endif()
 
 create_demo(texture texture.c)
 create_demo(font font.c)