diff --git a/Makefile.global b/Makefile.global
index 4fd796e3..cd489ef2 100644
--- a/Makefile.global
+++ b/Makefile.global
@@ -1,3 +1,4 @@
+# -*- makefile-gmake -*-
 # Here's the (hopefully simple) versioning scheme.
 #
 # Releases of notmuch have a two-digit version (0.1, 0.2, etc.). We
diff --git a/Makefile.local b/Makefile.local
index 39f36d50..156c8ce1 100644
--- a/Makefile.local
+++ b/Makefile.local
@@ -1,4 +1,4 @@
-# -*- makefile -*-
+# -*- makefile-gmake -*-
 
 .PHONY: all
 all: notmuch notmuch-shared build-man build-info ruby-bindings python-cffi-bindings
diff --git a/bindings/Makefile.local b/bindings/Makefile.local
index 19ddd6ea..bc960bbc 100644
--- a/bindings/Makefile.local
+++ b/bindings/Makefile.local
@@ -1,4 +1,4 @@
-# -*- makefile -*-
+# -*- makefile-gmake -*-
 
 dir := bindings
 
diff --git a/compat/Makefile.local b/compat/Makefile.local
index bcb9f0ec..2ee1b399 100644
--- a/compat/Makefile.local
+++ b/compat/Makefile.local
@@ -1,4 +1,4 @@
-# -*- makefile -*-
+# -*- makefile-gmake -*-
 
 dir := compat
 extra_cflags += -I$(srcdir)/$(dir)
diff --git a/completion/Makefile.local b/completion/Makefile.local
index 8e86c9d2..54df463c 100644
--- a/completion/Makefile.local
+++ b/completion/Makefile.local
@@ -1,4 +1,4 @@
-# -*- makefile -*-
+# -*- makefile-gmake -*-
 
 dir := completion
 
diff --git a/doc/Makefile.local b/doc/Makefile.local
index 30411341..60bd7184 100644
--- a/doc/Makefile.local
+++ b/doc/Makefile.local
@@ -1,4 +1,4 @@
-# -*- makefile -*-
+# -*- makefile-gmake -*-
 
 dir := doc
 
diff --git a/emacs/Makefile.local b/emacs/Makefile.local
index 141f5868..d1b320c3 100644
--- a/emacs/Makefile.local
+++ b/emacs/Makefile.local
@@ -1,4 +1,4 @@
-# -*- makefile -*-
+# -*- makefile-gmake -*-
 
 dir := emacs
 emacs_sources := \
diff --git a/lib/Makefile.local b/lib/Makefile.local
index 5dc057c0..a6400126 100644
--- a/lib/Makefile.local
+++ b/lib/Makefile.local
@@ -1,4 +1,4 @@
-# -*- makefile -*-
+# -*- makefile-gmake -*-
 
 dir := lib
 
diff --git a/parse-time-string/Makefile.local b/parse-time-string/Makefile.local
index 53534f3e..ee8030cc 100644
--- a/parse-time-string/Makefile.local
+++ b/parse-time-string/Makefile.local
@@ -1,3 +1,5 @@
+# -*- makefile-gmake -*-
+
 dir := parse-time-string
 extra_cflags += -I$(srcdir)/$(dir)
 
diff --git a/performance-test/Makefile.local b/performance-test/Makefile.local
index 9dc260e3..b9f580c7 100644
--- a/performance-test/Makefile.local
+++ b/performance-test/Makefile.local
@@ -1,4 +1,4 @@
-# -*- makefile -*-
+# -*- makefile-gmake -*-
 
 dir := performance-test
 
diff --git a/test/Makefile.local b/test/Makefile.local
index 47244e8f..40574739 100644
--- a/test/Makefile.local
+++ b/test/Makefile.local
@@ -1,4 +1,4 @@
-# -*- makefile -*-
+# -*- makefile-gmake -*-
 
 dir := test
 
diff --git a/util/Makefile.local b/util/Makefile.local
index f5d72f79..7ef029a5 100644
--- a/util/Makefile.local
+++ b/util/Makefile.local
@@ -1,4 +1,4 @@
-# -*- makefile -*-
+# -*- makefile-gmake -*-
 
 dir := util
 extra_cflags += -I$(srcdir)/$(dir)