diff --git a/environment-modules-tcl86.patch b/environment-modules-tcl86.patch
new file mode 100644
index 0000000..73b0b02
--- /dev/null
+++ b/environment-modules-tcl86.patch
@@ -0,0 +1,27 @@
+diff -up modules-3.2.10/cmdModule.c.tcl86 modules-3.2.10/cmdModule.c
+--- modules-3.2.10/cmdModule.c.tcl86	2012-11-01 16:02:19.000000000 -0600
++++ modules-3.2.10/cmdModule.c	2014-05-27 15:25:50.531554880 -0600
+@@ -56,7 +56,11 @@ static void *UseId[] = { &UseId, Id };
+ /**				      MACROS				     **/
+ /** ************************************************************************ **/
+ 
+-/** not applicable **/
++/** For Tcl < 8.6 compatibility **/
++#if (TCL_MAJOR_VERSION < 8) || (TCL_MAJOR_VERSION == 8) && (TCL_MINOR_VERSION < 6)
++#define Tcl_GetErrorLine(interp) (interp->errorLine)
++#define Tcl_SetErrorLine(interp,lineNum) (interp->errorLine = lineNum)
++#endif
+ 
+ /** ************************************************************************ **/
+ /** 				    LOCAL DATA				     **/
+@@ -640,8 +644,8 @@ int	 Execute_TclFile(	Tcl_Interp	*interp
+             case TCL_OK:	gotPartial = 0;
+ 			        continue;	/** while **/
+ 	    
+-            case TCL_ERROR:	interp->errorLine = ((linenum-1)-gotPartial) +
+-				    interp->errorLine;
++            case TCL_ERROR:	Tcl_SetErrorLine(interp, ((linenum-1)-gotPartial) +
++							 Tcl_GetErrorLine(interp));
+ 	    			/* FALLTHROUGH */
+ 
+             case TCL_LEVEL0_RETURN:
diff --git a/environment-modules.spec b/environment-modules.spec
index 6d55695..09fab5c 100644
--- a/environment-modules.spec
+++ b/environment-modules.spec
@@ -26,6 +26,9 @@ Patch3:         environment-modules-avail.patch
 # https://bugzilla.redhat.com/show_bug.cgi?id=1037053
 # https://sourceforge.net/p/modules/patches/13/
 Patch4:         environment-modules-format.patch
+# Support Tcl 8.6
+# https://sourceforge.net/p/modules/feature-requests/14/
+Patch5:         environment-modules-tcl86.patch
 
 BuildRequires:  tcl-devel, tclx-devel, libX11-devel
 BuildRequires:  dejagnu
@@ -68,6 +71,7 @@ have access to the module alias.
 %patch2 -p1 -b .clear
 %patch3 -p1 -b .avail
 %patch4 -p1 -b .format
+%patch5 -p1 -b .tcl86
 
 
 %build
@@ -127,6 +131,9 @@ fi
 
 
 %changelog
+* Tue May 27 2014 Orion Poplwski <orion@cora.nwra.com> - 3.2.10-10
+- Add patch to support Tcl 8.6
+
 * Wed May 21 2014 Jaroslav Škarvada <jskarvad@redhat.com> - 3.2.10-10
 - Rebuilt for https://fedoraproject.org/wiki/Changes/f21tcl86