diff --git a/scripts/lib.prov.files b/scripts/lib.prov.files
index 2651a63..0503ff2 100755
--- a/scripts/lib.prov.files
+++ b/scripts/lib.prov.files
@@ -1,7 +1,7 @@
 #!/bin/sh -efu
 while IFS=$'\t' read -r f t; do
 	case "$t" in
-		*ELF*" shared object"*)
+		*ELF*' shared object'*)
 			echo "$f" ;;
 	esac
 done
diff --git a/scripts/lib.req.files b/scripts/lib.req.files
index 7cdcdd6..eb14c30 100755
--- a/scripts/lib.req.files
+++ b/scripts/lib.req.files
@@ -1,9 +1,9 @@
 #!/bin/sh -efu
 while IFS=$'\t' read -r f t; do
 	case "$t" in
-		*ELF*" shared object"*)
+		*ELF*' shared object'*)
 			echo "$f" ;;
-		*ELF*" executable"*"dynamically linked"*)
+		*ELF*' executable'*'dynamically linked'*)
 			[ -x "$f" ] && echo "$f" ||
 			echo "${0##*/}: ELF executable $f not executable" >&2 ;;
 	esac
diff --git a/scripts/pkgconfig.req.files b/scripts/pkgconfig.req.files
index 1515167..0e01276 100755
--- a/scripts/pkgconfig.req.files
+++ b/scripts/pkgconfig.req.files
@@ -7,8 +7,8 @@ while IFS=$'\t' read -r f t; do
 		*) continue ;;
 	esac
 	case "$t" in
-		*" text"*) echo "$f" ;;
-		*"symbolic link to "*) ;;
+		*' text'*) echo "$f" ;;
+		*'symbolic link to '*) ;;
 		*) echo "${0##*/}: $f: $t" >&2 ;;
 	esac
 done
diff --git a/scripts/shebang.req.files b/scripts/shebang.req.files
index 2f4838e..fe7d11f 100755
--- a/scripts/shebang.req.files
+++ b/scripts/shebang.req.files
@@ -1,7 +1,7 @@
 #!/bin/sh -efu
 while IFS=$'\t' read -r f t; do
 	case "$t" in
-		*"script text executable"*)
+		*'script text executable'*)
 			[ -x "$f" ] && echo "$f" ||
 			echo "${0##*/}: executable script $f not executable" >&2 ;;
 	esac
diff --git a/scripts/shell.req.files b/scripts/shell.req.files
index 7721647..4549055 100755
--- a/scripts/shell.req.files
+++ b/scripts/shell.req.files
@@ -2,16 +2,16 @@
 while IFS=$'\t' read -r f t; do
 	case "$t" in
 		#!/bin/sh
-		*"Bourne shell script text"*)
+		*'Bourne shell script text'*)
 			echo "$f" ;;
 		#!/bin/bash
-		*"Bourne-Again shell script text"*)
+		*'Bourne-Again shell script text'*)
 			echo "$f" ;;
 		#!/usr/bin/env bash
-		*" bash script text"*)
+		*' bash script text'*)
 			echo "$f" ;;
 		#!/bin/ash
-		*" /bin/ash script text"*)
+		*' /bin/ash script text'*)
 			echo "$f" ;;
 	esac
 done