diff --git a/configs/autoconf.in b/configs/autoconf.in
index 4e931a3..a484bcf 100644
--- a/configs/autoconf.in
+++ b/configs/autoconf.in
@@ -58,6 +58,10 @@ INSTALL = @INSTALL@
 PYTHON2 = @PYTHON2@
 PYTHON_FLAGS = -t -O -O
 
+# Flex and Bison for GLSL compiler
+FLEX = @FLEX@
+BISON = @BISON@
+
 # Library names (base name)
 GL_LIB = GL
 GLU_LIB = GLU
diff --git a/configs/default b/configs/default
index 0582a02..b7acfd2 100644
--- a/configs/default
+++ b/configs/default
@@ -38,6 +38,8 @@ MKLIB_OPTIONS =
 MKDEP = makedepend
 MKDEP_OPTIONS = -fdepend
 MAKE = make
+FLEX = flex
+BISON = bison
 
 # Use MINSTALL for installing libraries, INSTALL for everything else
 MINSTALL = $(SHELL) $(TOP)/bin/minstall
diff --git a/configure.ac b/configure.ac
index 54d9c29..1920a22 100644
--- a/configure.ac
+++ b/configure.ac
@@ -39,6 +39,12 @@ if test "x$MKDEP" = "x"; then
     AC_MSG_ERROR([makedepend is required to build Mesa])
 fi
 
+AC_PATH_PROG([FLEX], [flex])
+test "x$FLEX" = "x" && AC_MSG_ERROR([flex is needed to build Mesa])
+
+AC_PATH_PROG([BISON], [bison])
+test "x$BISON" = "x" && AC_MSG_ERROR([bison is needed to build Mesa])
+
 dnl Our fallback install-sh is a symlink to minstall. Use the existing
 dnl configuration in that case.
 AC_PROG_INSTALL
diff --git a/src/glsl/Makefile b/src/glsl/Makefile
index e4b992d..4100414 100644
--- a/src/glsl/Makefile
+++ b/src/glsl/Makefile
@@ -192,16 +192,16 @@ $(DRICORE_OBJ_DIR)/%.o : %.c
 	$(CC) -c $(INCLUDES) $(DRI_CFLAGS) $(DEFINES) $< -o $@
 
 glsl_lexer.cpp: glsl_lexer.ll
-	flex --nounistd -o$@  $<
+	$(FLEX) --nounistd -o$@  $<
 
 glsl_parser.cpp: glsl_parser.yy
-	bison -v -o "$@" -p "_mesa_glsl_" --defines=glsl_parser.h $<
+	$(BISON) -v -o "$@" -p "_mesa_glsl_" --defines=glsl_parser.h $<
 
 glcpp/glcpp-lex.c: glcpp/glcpp-lex.l
-	flex --nounistd -o$@  $<
+	$(FLEX) --nounistd -o$@  $<
 
 glcpp/glcpp-parse.c: glcpp/glcpp-parse.y
-	bison -v -o "$@" --defines=glcpp/glcpp-parse.h $<
+	$(BISON) -v -o "$@" --defines=glcpp/glcpp-parse.h $<
 
 builtin_compiler: $(GLSL2_OBJECTS) $(OBJECTS) builtin_stubs.o
 	$(APP_CXX) $(INCLUDES) $(CXXFLAGS) $(LDFLAGS) $(OBJECTS) $(GLSL2_OBJECTS) builtin_stubs.o -o $@
diff --git a/src/mesa/Makefile b/src/mesa/Makefile
index 03962e9..a903a26 100644
--- a/src/mesa/Makefile
+++ b/src/mesa/Makefile
@@ -75,10 +75,10 @@ main/api_exec_es2.c: main/APIspec.xml main/es_generator.py main/APIspecutil.py m
 	$(PYTHON2) $(PYTHON_FLAGS) main/es_generator.py -S main/APIspec.xml -V GLES2.0 > $@
 
 program/program_parse.tab.c program/program_parse.tab.h: program/program_parse.y
-	bison -v -d --output=program/program_parse.tab.c $<
+	$(BISON) -v -d --output=program/program_parse.tab.c $<
 
 program/lex.yy.c: program/program_lexer.l
-	flex --never-interactive --outfile=$@ $<
+	$(FLEX) --never-interactive --outfile=$@ $<
 
 ######################################################################
 # Helper libraries used by many drivers: