diff --git a/flex-yyleng.patch b/flex-yyleng.patch
new file mode 100644
index 0000000..6faa709
--- /dev/null
+++ b/flex-yyleng.patch
@@ -0,0 +1,116 @@
+Index: flex-2.5.37/gen.c
+===================================================================
+--- flex-2.5.37.orig/gen.c
++++ flex-2.5.37/gen.c
+@@ -1516,11 +1516,11 @@ void make_tables ()
+ 	if (yymore_used && !yytext_is_array) {
+ 		indent_puts ("YY_G(yytext_ptr) -= YY_G(yy_more_len); \\");
+ 		indent_puts
+-			("yyleng = (size_t) (yy_cp - YY_G(yytext_ptr)); \\");
++			("yyleng = (int) (yy_cp - YY_G(yytext_ptr)); \\");
+ 	}
+ 
+ 	else
+-		indent_puts ("yyleng = (size_t) (yy_cp - yy_bp); \\");
++		indent_puts ("yyleng = (int) (yy_cp - yy_bp); \\");
+ 
+ 	/* Now also deal with copying yytext_ptr to yytext if needed. */
+ 	skelout ();		/* %% [3.0] - break point in skel */
+Index: flex-2.5.37/scan.c
+===================================================================
+--- flex-2.5.37.orig/scan.c
++++ flex-2.5.37/scan.c
+@@ -158,7 +158,7 @@ typedef struct yy_buffer_state *YY_BUFFE
+ typedef size_t yy_size_t;
+ #endif
+ 
+-extern yy_size_t yyleng;
++extern int yyleng;
+ 
+ extern FILE *yyin, *yyout;
+ 
+@@ -272,7 +272,7 @@ static YY_BUFFER_STATE * yy_buffer_stack
+ /* yy_hold_char holds the character lost when yytext is formed. */
+ static char yy_hold_char;
+ static yy_size_t yy_n_chars;		/* number of characters read into yy_ch_buf */
+-yy_size_t yyleng;
++int yyleng;
+ 
+ /* Points to current character in buffer. */
+ static char *yy_c_buf_p = (char *) 0;
+@@ -356,7 +356,7 @@ static void yy_fatal_error (yyconst char
+ #define YY_DO_BEFORE_ACTION \
+ 	(yytext_ptr) = yy_bp; \
+ 	(yytext_ptr) -= (yy_more_len); \
+-	yyleng = (size_t) (yy_cp - (yytext_ptr)); \
++	yyleng = (int) (yy_cp - (yytext_ptr)); \
+ 	(yy_hold_char) = *yy_cp; \
+ 	*yy_cp = '\0'; \
+ 	(yy_c_buf_p) = yy_cp;
+@@ -2036,7 +2036,7 @@ FILE *yyget_out (void );
+ 
+ void yyset_out  (FILE * out_str  );
+ 
+-yy_size_t yyget_leng (void );
++int yyget_leng (void );
+ 
+ char *yyget_text (void );
+ 
+@@ -4968,7 +4968,7 @@ FILE *yyget_out  (void)
+ /** Get the length of the current token.
+  * 
+  */
+-yy_size_t yyget_leng  (void)
++int yyget_leng  (void)
+ {
+         return yyleng;
+ }
+Index: flex-2.5.37/skel.c
+===================================================================
+--- flex-2.5.37.orig/skel.c
++++ flex-2.5.37/skel.c
+@@ -536,7 +536,7 @@ const char *skel[] = {
+   "#endif",
+   "",
+   "%if-not-reentrant",
+-  "extern yy_size_t yyleng;",
++  "extern int yyleng;",
+   "%endif",
+   "",
+   "%if-c-only",
+@@ -712,7 +712,7 @@ const char *skel[] = {
+   "/* yy_hold_char holds the character lost when yytext is formed. */",
+   "static char yy_hold_char;",
+   "static yy_size_t yy_n_chars;		/* number of characters read into yy_ch_buf */",
+-  "yy_size_t yyleng;",
++  "int yyleng;",
+   "",
+   "/* Points to current character in buffer. */",
+   "static char *yy_c_buf_p = (char *) 0;",
+@@ -875,7 +875,7 @@ const char *skel[] = {
+   "    YY_BUFFER_STATE * yy_buffer_stack; /**< Stack as an array. */",
+   "    char yy_hold_char;",
+   "    yy_size_t yy_n_chars;",
+-  "    yy_size_t yyleng_r;",
++  "    int yyleng_r;",
+   "    char *yy_c_buf_p;",
+   "    int yy_init;",
+   "    int yy_start;",
+@@ -1012,7 +1012,7 @@ const char *skel[] = {
+   "",
+   "m4_ifdef( [[M4_YY_NO_GET_LENG]],,",
+   "[[",
+-  "yy_size_t yyget_leng M4_YY_PARAMS( M4_YY_PROTO_ONLY_ARG );",
++  "int yyget_leng M4_YY_PARAMS( M4_YY_PROTO_ONLY_ARG );",
+   "]])",
+   "",
+   "m4_ifdef( [[M4_YY_NO_GET_TEXT]],,",
+@@ -2792,7 +2792,7 @@ const char *skel[] = {
+   "/** Get the length of the current token.",
+   " * M4_YY_DOC_PARAM",
+   " */",
+-  "yy_size_t yyget_leng  YYFARGS0(void)",
++  "int yyget_leng  YYFARGS0(void)",
+   "{",
+   "    M4_YY_DECL_GUTS_VAR();",
+   "    return yyleng;",
diff --git a/flex.changes b/flex.changes
index fa5c0ab..12262f1 100644
--- a/flex.changes
+++ b/flex.changes
@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Sun Feb 15 17:45:41 UTC 2015 - schwab@linux-m68k.org
+
+- flex-yyleng.patch: fix type of yyleng to be int as mandated by POSIX.
+  Fixes perl-SystemPerl, for example.
+
 -------------------------------------------------------------------
 Mon Jan  5 11:35:08 UTC 2015 - mlin@suse.com
 
diff --git a/flex.spec b/flex.spec
index 90cb9a4..f7e0ee5 100644
--- a/flex.spec
+++ b/flex.spec
@@ -47,6 +47,8 @@ Patch3:         http://www.linuxfromscratch.org/patches/lfs/7.2/flex-2.5.37-biso
 # PATCH-FIX-UPSTREAM flex-2.5.37-bison3.patch mlin@suse.com - fix tests for bison3
 Patch4:         flex-compatible-with-bison3.patch
 Patch5:         config-guess-sub-update.patch
+# PATCH-FIX-UPSTREAM fix type of yyleng as mandated by POSIX (flex bug #187)
+Patch6:         flex-yyleng.patch
 BuildRoot:      %{_tmppath}/%{name}-%{version}-build
 
 %description
@@ -60,6 +62,7 @@ patterns in text.
 %patch3 -p1
 %patch4 -p1
 %patch5
+%patch6 -p1
 
 %build
 autoreconf -fi