diff --git a/Makefile.config b/Makefile.config
deleted file mode 100644
index ddc74365..00000000
--- a/Makefile.config
+++ /dev/null
@@ -1,3 +0,0 @@
-prefix = /usr/local
-bash_completion_dir = /etc/bash_completion.d
-CFLAGS += -DHAVE_VALGRIND
diff --git a/configure b/configure
index e55f067e..ab28fa30 100755
--- a/configure
+++ b/configure
@@ -1,5 +1,15 @@
 #! /bin/sh
 
+# defaults
+PREFIX=/usr/local
+
+# option parsing
+for option; do
+    if [ "${option%=*}" = '--prefix' ] ; then
+	PREFIX="${option#*=}"
+    fi
+done
+
 cat <<EOF
 Welcome to Notmuch, a system for indexing, searching and tagging your email.
 
@@ -130,7 +140,7 @@ EOF
 
 # construct the Makefile.config
 cat > Makefile.config <<EOF
-prefix = /usr/local
+prefix = $PREFIX
 bash_completion_dir = /etc/bash_completion.d
 CFLAGS += ${have_valgrind}
 EOF