diff --git a/configure b/configure
index 7e0700e..af2d2ed 100755
--- a/configure
+++ b/configure
@@ -101,7 +101,7 @@ EOF
 }
 
 build_mk_append_man_generic() {
-	cat <<'EOF' >> "$1"
+    cat <<'EOF' >> "$1"
 MANDIR		= $(PREFIX)/share/man
 EOF
 }
@@ -113,7 +113,7 @@ build_mk_append_man_bsd() {
         local mandir='$(PREFIX)/man'
     fi
 
-	cat <<EOF >> "$1"
+    cat <<EOF >> "$1"
 MANDIR		= $mandir
 EOF
 }
@@ -142,8 +142,8 @@ build_mk_create() {
         cat <<'EOF' > "$1"
 CGFLAGS		= -g -fno-inline
 EOF
-	else
-		cat <<'EOF' > "$1"
+    else
+        cat <<'EOF' > "$1"
 CGFLAGS		=
 EOF
     fi
@@ -154,7 +154,7 @@ EOF
         build_mk_append_generic "$1"
     fi
 
-	case $OS in
+    case $OS in
         FreeBSD|NetBSD|OpenBSD)
             build_mk_append_man_bsd "$1"
         ;;
@@ -162,9 +162,9 @@ EOF
         *)
             build_mk_append_man_generic "$1"
         ;;
-	esac
+    esac
 
-	cat <<'EOF' >> "$1"
+    cat <<'EOF' >> "$1"
 CWFLAGS		= -Wall
 COFLAGS		= -O2
 CFLAGS		= $(CGFLAGS) $(CWFLAGS) $(COFLAGS)