diff --git a/2013/endoh2/Makefile b/2013/endoh2/Makefile
index 91d0f197d..f6d7e81cd 100644
--- a/2013/endoh2/Makefile
+++ b/2013/endoh2/Makefile
@@ -146,6 +146,29 @@ jpeg.jpg: jpeg
 
 check: ${DATA}
 	${RM} -f jpeg2.c
+	@if ! type -P convert >/dev/null 2>&1; then \
+	    echo "The 'convert' tool from ImageMagick could not be found." 1>&2; \
+	    echo ""; 1>&2; \
+	    echo "See the following website for ImageMagick:" 1>&2; \
+	    echo ""; 1>&2; \
+	    echo "    https://imagemagick.org/script/download.php"; 1>&2; \
+	    echo ""; 1>&2; \
+	    echo "or use your OS package manager to install it." 1>&2; \
+	fi
+	@if ! type -P ${RUBY} >/dev/null 2>&1; then \
+	    echo "${RUBY} language could not be found." 1>&2; \
+	    echo "${RUBY} must be installed in order to run the $@ rule." 1>&2; \
+	    echo ""; 1>&2; \
+	    echo "See the following website for ${RUBY}:" 1>&2; \
+	    echo ""; 1>&2; \
+	    echo "    https://www.ruby-lang.org/"; 1>&2; \
+	    echo ""; 1>&2; \
+	    echo "or use your OS package manager to install it." 1>&2; \
+	    ERROR=1; \
+	fi
+	@if type -P ${RUBY} >/dev/null 2>&1 || ! type -P convert >/dev/null 2>&1; then \
+	    exit 1; \
+	fi
 	${RUBY} ocr.rb jpeg.jpg > jpeg2.c
 	${DIFF} jpeg.c jpeg2.c && echo Check succeeded
 
diff --git a/2013/endoh2/README.md b/2013/endoh2/README.md
index 271e0bc5b..38a48d7a6 100644
--- a/2013/endoh2/README.md
+++ b/2013/endoh2/README.md
@@ -17,7 +17,14 @@ make
 make check
 ```
 
-You'll need to have Ruby installed to run all the automated checks.
+You'll need to have both [Ruby](https://www.ruby-lang.org) and
+[ImageMagick](https://imagemagick.org/) installed to run all the automated
+checks.
+
+If you do not have both, however, you can still do the below in the [try](#try)
+section to enjoy the entry. The [Makefile](Makefile) `check` rule will check if
+you have both and if either is not found it will report it and tell you where to
+download one or both before exiting.
 
 ## Try:
 
diff --git a/thanks-for-fixes.md b/thanks-for-fixes.md
index f6987b99b..88c6632a4 100644
--- a/thanks-for-fixes.md
+++ b/thanks-for-fixes.md
@@ -1654,6 +1654,26 @@ symlink is created.
 Cody also added the [demo.sh](2013/dlowe/demo.sh) script to more easily try the
 program.
 
+## [2013/endoh2](2013/endoh2/endoh2.c) ([README.md](2013/endoh2/README.md))
+
+Cody fixed the Makefile `check` rule so that it `checks` :-) that both
+[Ruby](https://www.ruby-lang.org) and [ImageMagick](https://imagemagick.org) are
+installed before trying to run the ruby script. To be more technically correct:
+it checks that the `convert` tool of ImageMagick is available (via `type -P`)
+because `convert` is part of the ImageMagick suite.
+
+This is useful because the Ruby script tries to run (via `IO.popen()`) the
+`convert` tool but without ImageMagick being installed, if one is unaware of
+where it comes from it will appear to be an error in the Ruby script (it might
+also appear to be an issue with the script even if you know of `convert`: it was
+another day that Cody remembered it and why it wasn't installed on his MacBook
+Pro even though in the past it had been and is indeed now).
+
+The rule will report the tools not installed and where to find them, if they are
+not installed, and after checking these requirements it will exit if either is
+not found.
+
+The entry can still be enjoyed if you do not have these tools, however.
 
 ## [2013/endoh4](2013/endoh4/endoh4.c) ([README.md](2013/endoh4/README.md))