diff --git a/libs/util/cexpr-lex.l b/libs/util/cexpr-lex.l
index 0bb03246d..2c696dfee 100644
--- a/libs/util/cexpr-lex.l
+++ b/libs/util/cexpr-lex.l
@@ -55,8 +55,10 @@
 #include "QF/cexpr.h"
 #include "libs/util/cexpr-parse.h"
 
-#define YY_NO_INPUT
-#define YY_NO_UNPUT
+#define YY_NO_INPUT	// debian flex
+#define YY_NO_UNPUT	// debian flex
+#define YY_NO_YYINPUT
+#define YY_NO_YYUNPUT
 
 #define YYSTYPE CEXPR_YYSTYPE
 #define YY_EXTRA_TYPE exprctx_t *
diff --git a/tools/qfcc/source/qc-lex.l b/tools/qfcc/source/qc-lex.l
index 303694161..b1c40a214 100644
--- a/tools/qfcc/source/qc-lex.l
+++ b/tools/qfcc/source/qc-lex.l
@@ -68,7 +68,10 @@
 # define YY_FLEX_REALLOC_HACK
 #endif
 
-#define YY_NO_UNPUT
+#define YY_NO_INPUT	// debian flex
+#define YY_NO_UNPUT	// debian flex
+#define YY_NO_YYINPUT
+#define YY_NO_YYUNPUT
 #define YY_DECL int yylex YY_PROTO(( void ))
 YY_DECL;
 
@@ -767,12 +770,3 @@ parse_float_vector (const char *token, int width)
 	expr->implicit = !t;
 	return expr;
 }
-
-#ifdef YY_FLEX_REALLOC_HACK
-static __attribute__ ((used)) void *(*const yy_flex_realloc_hack)(void *,yy_size_t) = yy_flex_realloc;
-#else
-#ifdef yyunput
-static __attribute__ ((used)) void (*yyunput_hack)(int, char*) = yyunput;
-#endif
-static __attribute__ ((used)) int (*input_hack)(void) = input;
-#endif
diff --git a/tools/qfcc/source/qp-lex.l b/tools/qfcc/source/qp-lex.l
index 7bb6d160b..e9da94d32 100644
--- a/tools/qfcc/source/qp-lex.l
+++ b/tools/qfcc/source/qp-lex.l
@@ -53,7 +53,10 @@
 # define YY_FLEX_REALLOC_HACK
 #endif
 
-#define YY_NO_UNPUT
+#define YY_NO_INPUT	// debian flex
+#define YY_NO_UNPUT	// debian flex
+#define YY_NO_YYINPUT
+#define YY_NO_YYUNPUT
 #define YY_DECL int yylex YY_PROTO(( void ))
 YY_DECL;
 
@@ -299,13 +302,3 @@ convert_relop (const char *relop)
 	}
 	internal_error (0, "bad relop %s", relop);
 }
-
-#ifdef YY_FLEX_REALLOC_HACK
-static __attribute__ ((used)) void *(*const yy_flex_realloc_hack)(void *,yy_size_t) = yy_flex_realloc;
-#else
-#ifdef yyunput
-static __attribute__ ((used)) void (*yyunput_hack)(int, char*) = yyunput;
-#endif
-static __attribute__ ((used)) int (*input_hack)(void) = input;
-#endif
-