diff --git a/Makefile b/Makefile
index ccdb78c976bd14b204a97fc8d84099578edd099a..c14bf58b2a1e95224c7482d23d1e1ecf45024b24 100644
--- a/Makefile
+++ b/Makefile
@@ -82,7 +82,7 @@ dontrun:
 
 $(Frama_Clang_DIR)/gen_ast: $(PLUGIN_DIR)/gen_ast.ml
 	$(PRINT_OCAMLC) $@
-	$(OCAMLC) $(Frama_Clang_BFLAGS) -o $@ -pp $(CAMLP4O) \
+	$(OCAMLC) $(Frama_Clang_BFLAGS) -o $@ -pp $(CAMLP5O) \
         zarith.cma dynlink.cma transitioning.cmo $^
 
 $(Frama_Clang_DIR)/test_ast: \
diff --git a/Makefile.config.in b/Makefile.config.in
index df86b9379e39495919f99a6bd09b03d39ab2a7ce..fdc86b23d3504d7c1788e9956ee6a0c407688ffe 100644
--- a/Makefile.config.in
+++ b/Makefile.config.in
@@ -21,7 +21,7 @@
 ##########################################################################
 
 ENABLE_FRAMA_CLANG=@ENABLE_FRAMA_CLANG@
-CAMLP4O=@CAMLP4O@
+CAMLP5O=@CAMLP5O@
 CXX=@CXX@
 CLANG_CXXFLAGS=@CLANG_CXXFLAGS@
 CLANG_CFLAGS=@CLANG_CFLAGS@
diff --git a/configure.ac b/configure.ac
index aecc826cc7bdadb249f964de7de7c583389741f2..a903c5810ed8026d4aac86ae67cb3ac4589ebf9e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -36,14 +36,14 @@ m4_ifndef([FRAMAC_M4_MACROS],
 check_plugin([frama_clang],PLUGIN_RELATIVE_PATH(plugin_file),
              [C++ front-end for Frama-C],yes)
 
-plugin_require_external(frama_clang,camlp4o)
+plugin_require_external(frama_clang,camlp5o)
 
 # check for system C++ compiler, as we can't rely on clang++ itself because
 # of potential incompatibilities with GNU libstdc++ v5.
 # See https://llvm.org/bugs/show_bug.cgi?id=23529 for more details
 AC_PROG_CXX()
 
-configure_tool([CAMLP4O],[camlp4o],[camlp4o not found.],no)
+configure_tool([CAMLP5O],[camlp5o],[camlp5o not found.],no)
 check_plugin_dependencies()
 
 AC_SUBST(CLANG_CXXFLAGS)