diff --git a/Makefile b/Makefile
index 0a56a82..2f4adde 100644
--- a/Makefile
+++ b/Makefile
@@ -41,8 +41,8 @@ clean:
 	$(MAKE) -C embed clean
 
 docs: README.md doc/ctpv.1
-	deptable/list.awk $(PRE) | deptable/markdown.sh | deptable/insert.sh README.md
-	deptable/list.awk $(PRE) | deptable/roff.sh     | deptable/insert.sh doc/ctpv.1
+	deptable/list.awk $(PRE) | deptable/markdown.sed | deptable/insert.awk README.md
+	deptable/list.awk $(PRE) | deptable/roff.sed | deptable/insert.awk doc/ctpv.1
 
 ctpv: $(OBJ)
 	$(CC) -o $@ $+ $(LDFLAGS)
diff --git a/deptable/insert.awk b/deptable/insert.awk
new file mode 100755
index 0000000..2aa3bbf
--- /dev/null
+++ b/deptable/insert.awk
@@ -0,0 +1,20 @@
+#!/usr/bin/gawk -f
+
+@include "inplace"
+
+BEGIN {
+    while ((getline line < "-") > 0)
+        input = input line "\n"
+    close("-")
+}
+
+/TABLEEND/ {
+    table = 0
+    printf "%s", input
+}
+
+!table
+
+/TABLESTART/ {
+    table = 1
+}
diff --git a/deptable/insert.sh b/deptable/insert.sh
deleted file mode 100755
index 4615042..0000000
--- a/deptable/insert.sh
+++ /dev/null
@@ -1,21 +0,0 @@
-#!/bin/sh
-
-set -e
-
-tmp="$(mktemp XXXXXX)"
-table="$(mktemp XXXXXX)"
-trap 'rm "$table"' EXIT
-
-cat > "$table"
-
-sed "
-	/TABLESTART/,/TABLEEND/ {
-		/TABLESTART/ {
-			r $table
-			b
-		}
-		/TABLEEND/!d
-	}
-" "$1" > "$tmp"
-
-mv -- "$tmp" "$1"
diff --git a/deptable/list.awk b/deptable/list.awk
index 33e6c17..276aeb5 100755
--- a/deptable/list.awk
+++ b/deptable/list.awk
@@ -38,5 +38,7 @@ BEGIN {
         process_file(ARGV[i])
 
     for (t in types)
-        printf "%s\t%s\n", t, join(types[t], " ")
+        s = s sprintf("%s\t%s\n", t, join(types[t], " "))
+
+    printf "%s", s | "sort"
 }
diff --git a/deptable/markdown.sed b/deptable/markdown.sed
new file mode 100755
index 0000000..539366d
--- /dev/null
+++ b/deptable/markdown.sed
@@ -0,0 +1,16 @@
+#!/bin/sed -f
+
+# Add header
+1i\
+| File types | Programs |\
+| ---- | ---- |
+
+# Format rows
+s/ /` `/g
+s/\t/ | `/
+s/^/| /
+s/$/` |/
+
+# Add a newline at the end
+$a\
+
diff --git a/deptable/markdown.sh b/deptable/markdown.sh
deleted file mode 100755
index 4671645..0000000
--- a/deptable/markdown.sh
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/bin/sh
-
-echo "| File types | Programs |"
-echo "| ---- | ---- |"
-
-sort | sed 's/ /` `/g; s/^/| /; s/\t/ | `/; s/$/` |/'
-echo
diff --git a/deptable/roff.sed b/deptable/roff.sed
new file mode 100755
index 0000000..7e37fec
--- /dev/null
+++ b/deptable/roff.sed
@@ -0,0 +1,16 @@
+#!/bin/sed -f
+
+# Add header
+1i\
+.TS\
+allbox;\
+lb lb\
+l li .\
+File type\tPrograms
+
+# Format rows
+s/\t/&T{\n/; s/$/\nT}/
+
+# Add footer
+$a\
+.TE
diff --git a/deptable/roff.sh b/deptable/roff.sh
deleted file mode 100755
index 1932836..0000000
--- a/deptable/roff.sh
+++ /dev/null
@@ -1,11 +0,0 @@
-#!/bin/sh
-
-echo '.TS'
-echo 'allbox;'
-echo 'lb lb'
-echo 'l li .'
-
-printf '%s\t%s\n' 'File type' 'Programs'
-sort | sed 's/\t/&T{\n/; s/$/\nT}/'
-
-echo '.TE'