diff --git a/doc/src/manual/environment-variables.md b/doc/src/manual/environment-variables.md
index abbf9a842f288..211ccfc6c46da 100644
--- a/doc/src/manual/environment-variables.md
+++ b/doc/src/manual/environment-variables.md
@@ -396,18 +396,18 @@ affinitized. Otherwise, Julia lets the operating system handle thread policy.
 
 ### [`JULIA_HEAP_SIZE_HINT`](@id JULIA_HEAP_SIZE_HINT)
 
-Environment variable equivalent to the `--heap-size-hint` command line option.
+Environment variable equivalent to the `--heap-size-hint=<size>[<unit>]` command line option.
 
 Forces garbage collection if memory usage is higher than the given value. The value may be specified as a number of bytes, optionally in units of:
 
-    - b  (bytes)
-    - k  (kibibytes)
-    - m  (mebibytes)
-    - g  (gibibytes)
-    - t  (tebibytes)
+    - B  (bytes)
+    - K  (kibibytes)
+    - M  (mebibytes)
+    - G  (gibibytes)
+    - T  (tebibytes)
     - %  (percentage of physical memory)
 
-which are not case sensitive. For example, `JULIA_HEAP_SIZE_HINT=1G` would provide a 1 GB heap size hint to the garbage collector.
+For example, `JULIA_HEAP_SIZE_HINT=1G` would provide a 1 GB heap size hint to the garbage collector.
 
 ## REPL formatting
 
diff --git a/src/jloptions.c b/src/jloptions.c
index 71b0368edd1c4..a00b4c6d8cce0 100644
--- a/src/jloptions.c
+++ b/src/jloptions.c
@@ -281,8 +281,9 @@ static const char opts[]  =
     "                                               information, see --bug-report=help.\n\n"
     " --heap-size-hint=<size>[<unit>]               Forces garbage collection if memory usage is higher\n"
     "                                               than the given value. The value may be specified as a\n"
-    "                                               number of bytes, optionally in units of: B, KB, MB,\n"
-    "                                               GB, TB, or as a percentage of physical memory (%)\n\n"
+    "                                               number of bytes, optionally in units of: B, K (kilobytes),\n"
+    "                                               M (megabytes), G (gigabytes), T (terabytes), or % (percentage\n"
+    "                                               of physical memory).\n\n"
 ;
 
 static const char opts_hidden[]  =