diff --git a/tests/Internals/bash b/tests/Internals/bash
new file mode 100755
index 0000000..ea2bd0b
--- /dev/null
+++ b/tests/Internals/bash
@@ -0,0 +1 @@
+run '!#/bin/bash'
diff --git a/tests/Internals/empty b/tests/Internals/empty
new file mode 100755
index 0000000..5486748
--- /dev/null
+++ b/tests/Internals/empty
@@ -0,0 +1 @@
+! run ''
diff --git a/tests/Internals/empty-line b/tests/Internals/empty-line
new file mode 100755
index 0000000..db0491e
--- /dev/null
+++ b/tests/Internals/empty-line
@@ -0,0 +1,5 @@
+! run '
+
+
+
+'
diff --git a/tests/Internals/env b/tests/Internals/env
new file mode 100755
index 0000000..c6f4a9b
--- /dev/null
+++ b/tests/Internals/env
@@ -0,0 +1 @@
+run '!#/usr/bin/env true'
diff --git a/tests/Internals/has_shebang_line b/tests/Internals/has_shebang_line
deleted file mode 100755
index ad612f4..0000000
--- a/tests/Internals/has_shebang_line
+++ /dev/null
@@ -1,20 +0,0 @@
-TESTING_URCHIN_INTERNALS=true . ../../urchin
-
-echo '!#/bin/sh' > $tmp
-! has_shebang_line $tmp
-
-echo '!#/bin/bash' > $tmp
-has_shebang_line $tmp
-
-echo '!#/usr/bin/env true' > $tmp
-has_shebang_line $tmp
-
-echo > $tmp
-! has_shebang_line $tmp
-
-echo '
-
-
-
-' > $tmp
-! has_shebang_line $tmp
diff --git a/tests/Internals/setup b/tests/Internals/setup
index e01b6ff..35878ac 100644
--- a/tests/Internals/setup
+++ b/tests/Internals/setup
@@ -1 +1,7 @@
 export tmp=$(mktemp)
+
+run() {
+  TESTING_URCHIN_INTERNALS=true . ../../urchin
+  echo "$1" > $tmp
+  has_shebang_line $tmp
+}
diff --git a/tests/Internals/sh b/tests/Internals/sh
new file mode 100755
index 0000000..80fb3de
--- /dev/null
+++ b/tests/Internals/sh
@@ -0,0 +1 @@
+! run '!#/bin/sh'
diff --git a/urchin b/urchin
index f3dc0d9..e369087 100755
--- a/urchin
+++ b/urchin
@@ -414,7 +414,7 @@ report_outcome() {
 }
 
 has_shebang_line() {
-  head -n 1 "${1}" | grep -q -v '^#!/bin/sh'
+  head -n 1 "${1}" | grep -v '^#!/bin/sh$' | grep -q '^#!'
 }
 
 USAGE="usage: $0 [options]... [test file or directory]..."