diff --git a/headers/header_spec.txt b/headers/header_spec.txt
index 1c55a010a9a2b4f070879daa5aadca788cad5b06..7a47b2372ac463babda41ffa1acc5d37227c1bca 100644
--- a/headers/header_spec.txt
+++ b/headers/header_spec.txt
@@ -1108,7 +1108,7 @@ src/plugins/qed/cache.ml: CEA_WP
 src/plugins/qed/cache.mli: CEA_WP
 src/plugins/qed/collection.ml: CEA_WP
 src/plugins/qed/collection.mli: CEA_WP
-src/plugins/qed/engine.ml: CEA_WP
+src/plugins/qed/engine.mli: CEA_WP
 src/plugins/qed/export.ml: CEA_WP
 src/plugins/qed/export.mli: CEA_WP
 src/plugins/qed/export_altergo.ml: CEA_WP
@@ -1135,7 +1135,7 @@ src/plugins/qed/listmap.ml: CEA_WP
 src/plugins/qed/listmap.mli: CEA_WP
 src/plugins/qed/listset.ml: CEA_WP
 src/plugins/qed/listset.mli: CEA_WP
-src/plugins/qed/logic.ml: CEA_WP
+src/plugins/qed/logic.mli: CEA_WP
 src/plugins/qed/mergemap.ml: CEA_WP
 src/plugins/qed/mergemap.mli: CEA_WP
 src/plugins/qed/mergeset.ml: CEA_WP
diff --git a/src/plugins/qed/Makefile b/src/plugins/qed/Makefile
index 6fabefa9b84fbe75453a80a215b6931c13cacac9..fb2350efe6e9561f0bcbe3c3803c7b266b8bda09 100644
--- a/src/plugins/qed/Makefile
+++ b/src/plugins/qed/Makefile
@@ -50,14 +50,16 @@ PLUGIN_CMO:= \
 	idxmap idxset \
 	mergemap mergeset collection \
 	partition cache \
-	bvars logic \
+	bvars \
 	pool kind term \
-	plib pretty engine export \
+	plib pretty export \
 	export_whycore \
 	export_altergo \
 	export_why3 \
 	export_coq \
 
+PLUGIN_CMI:= logic engine
+
 PLUGIN_DEPENDENCIES:=
 PLUGIN_TESTS_DIRS:=
 PLUGIN_BFLAGS:=
@@ -81,9 +83,9 @@ QED_API= \
 	mergemap.mli mergeset.mli collection.mli \
 	partition.mli cache.mli \
 	bvars.mli \
-	logic.ml \
+	logic.mli \
 	pool.mli kind.mli term.mli \
-	plib.mli pretty.mli engine.ml export.mli \
+	plib.mli pretty.mli engine.mli export.mli \
 	export_whycore.mli \
 	export_altergo.mli \
 	export_why3.mli \
diff --git a/src/plugins/qed/engine.ml b/src/plugins/qed/engine.mli
similarity index 100%
rename from src/plugins/qed/engine.ml
rename to src/plugins/qed/engine.mli
diff --git a/src/plugins/qed/logic.ml b/src/plugins/qed/logic.mli
similarity index 100%
rename from src/plugins/qed/logic.ml
rename to src/plugins/qed/logic.mli