diff --git a/labltk-8.06.4-enable-more-debugging.patch b/labltk-8.06.4-enable-more-debugging.patch
new file mode 100644
index 0000000..f2a02e4
--- /dev/null
+++ b/labltk-8.06.4-enable-more-debugging.patch
@@ -0,0 +1,11 @@
+--- labltk-8.06.4.old/support/Makefile	2017-10-30 09:19:07.000000000 +0000
++++ labltk-8.06.4/support/Makefile	2017-11-07 21:24:58.244605912 +0000
+@@ -28,7 +28,7 @@
+       cltkFile.$(O) cltkMain.$(O) cltkMisc.$(O) cltkTimer.$(O) \
+       cltkVar.$(O) cltkWait.$(O) cltkImg.$(O)
+ 
+-CCFLAGS=-I$(LIBDIR)/caml $(TK_DEFS) $(SHAREDCCCOMPOPTS)
++CCFLAGS=-I$(LIBDIR)/caml $(TK_DEFS) $(SHAREDCCCOMPOPTS) -g
+ 
+ COMPFLAGS=
+ THFLAGS=-I +threads -I vmthreads
diff --git a/ocaml-labltk.spec b/ocaml-labltk.spec
index a42c4d7..416dac6 100644
--- a/ocaml-labltk.spec
+++ b/ocaml-labltk.spec
@@ -17,6 +17,7 @@ Source0:       https://forge.ocamlcore.org/frs/download.php/1727/labltk-8.06.4.t
 
 # This adds debugging (-g) everywhere.
 Patch1:        labltk-8.06.0-enable-debugging.patch
+Patch2:        labltk-8.06.4-enable-more-debugging.patch
 
 BuildRequires: ocaml
 BuildRequires: tcl-devel, tk-devel
@@ -44,6 +45,7 @@ This package contains the development files.
 %setup -q -n labltk-%{version}
 
 %patch1 -p1
+%patch2 -p1
 
 # Remove version control files which might get copied into documentation.
 find -name .gitignore -delete
@@ -108,6 +110,7 @@ install -m 0644 camltk/*.o $RPM_BUILD_ROOT%{_libdir}/ocaml/labltk
 %changelog
 * Tue Nov 07 2017 Richard W.M. Jones <rjones@redhat.com> - 8.06.4-2
 - OCaml 4.06.0 rebuild.
+- Add -g flag to all calls to gcc as well.
 
 * Tue Nov 07 2017 Richard W.M. Jones <rjones@redhat.com> - 8.06.4-1
 - New upstream version 8.06.4.