diff --git a/Make.rules.in b/Make.rules.in
index cc6d13cf627..894c377ade0 100644
--- a/Make.rules.in
+++ b/Make.rules.in
@@ -127,10 +127,10 @@ LINTS  = $(C_SRCS:.c=.ln)
 	$(AS) -o $@ $<
 
 .y.tab.c:
-	$(BISON) $(BISONFLAGS) -o $@ $<
+	$(BISON) $(BISONFLAGS) -p $*_ -o $@ $<
 
 .y.tab.h:
-	$(BISON) $(BISONFLAGS) -o $*.tab.c -d $<
+	$(BISON) $(BISONFLAGS) -p $*_ -o $*.tab.c -d $<
 
 .l.yy.c:
 	$(LEX) $(LEXFLAGS) -t $< >$@ || ($(RM) $@ && exit 1)
diff --git a/programs/winedbg/dbg.y b/programs/winedbg/dbg.y
index b7d83d81f5e..56efb94d19a 100644
--- a/programs/winedbg/dbg.y
+++ b/programs/winedbg/dbg.y
@@ -40,6 +40,8 @@ int yyerror(const char*);
 
 %}
 
+%name-prefix="yy"
+
 %union
 {
     struct dbg_lvalue   lvalue;
diff --git a/tools/widl/parser.y b/tools/widl/parser.y
index 63e4c6d5327..922df4d66b5 100644
--- a/tools/widl/parser.y
+++ b/tools/widl/parser.y
@@ -126,6 +126,8 @@ static void check_arg(var_t *arg);
 	unsigned int num;
 }
 
+%name-prefix="yy"
+
 %token <str> aIDENTIFIER
 %token <str> aKNOWNTYPE
 %token <num> aNUM aHEXNUM
diff --git a/tools/wmc/mcy.y b/tools/wmc/mcy.y
index 32458be9173..abe5d0253d6 100644
--- a/tools/wmc/mcy.y
+++ b/tools/wmc/mcy.y
@@ -95,6 +95,7 @@ static cp_xlat_t *find_cpxlat(int lan);
 
 %}
 
+%name-prefix="yy"
 
 %union {
 	WCHAR		*str;
diff --git a/tools/wrc/parser.y b/tools/wrc/parser.y
index bc7409e94fc..4297a1903dd 100644
--- a/tools/wrc/parser.y
+++ b/tools/wrc/parser.y
@@ -282,6 +282,8 @@ static int rsrcid_to_token(int lookahead);
 	ani_any_t	*ani;
 }
 
+%name-prefix="yy"
+
 %token tNL
 %token <num> tNUMBER tLNUMBER
 %token <str> tSTRING tIDENT tFILENAME