diff --git a/rescript-ecosystem/packages/core/compiler-source/tests/analysis_tests/tests-generic-jsx-transform/test.sh b/rescript-ecosystem/packages/core/compiler-source/tests/analysis_tests/tests-generic-jsx-transform/test.sh
index c58c8e70b..9e049e22e 100755
--- a/rescript-ecosystem/packages/core/compiler-source/tests/analysis_tests/tests-generic-jsx-transform/test.sh
+++ b/rescript-ecosystem/packages/core/compiler-source/tests/analysis_tests/tests-generic-jsx-transform/test.sh
@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 for file in src/*.res; do
   output="$(dirname $file)/expected/$(basename $file).txt"
   ../../../_build/install/default/bin/rescript-editor-analysis test $file &> $output
diff --git a/rescript-ecosystem/packages/core/compiler-source/tests/analysis_tests/tests-incremental-typechecking/test.sh b/rescript-ecosystem/packages/core/compiler-source/tests/analysis_tests/tests-incremental-typechecking/test.sh
index c58c8e70b..9e049e22e 100755
--- a/rescript-ecosystem/packages/core/compiler-source/tests/analysis_tests/tests-incremental-typechecking/test.sh
+++ b/rescript-ecosystem/packages/core/compiler-source/tests/analysis_tests/tests-incremental-typechecking/test.sh
@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 for file in src/*.res; do
   output="$(dirname $file)/expected/$(basename $file).txt"
   ../../../_build/install/default/bin/rescript-editor-analysis test $file &> $output
diff --git a/rescript-ecosystem/packages/core/compiler-source/tests/analysis_tests/tests-reanalyze/deadcode/test.sh b/rescript-ecosystem/packages/core/compiler-source/tests/analysis_tests/tests-reanalyze/deadcode/test.sh
index a408b9da0..b1ad21c1b 100755
--- a/rescript-ecosystem/packages/core/compiler-source/tests/analysis_tests/tests-reanalyze/deadcode/test.sh
+++ b/rescript-ecosystem/packages/core/compiler-source/tests/analysis_tests/tests-reanalyze/deadcode/test.sh
@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 DEBUG_FLAG="-debug"
 
 if [ "$RUNNER_OS" == "Windows" ]; then
diff --git a/rescript-ecosystem/packages/core/compiler-source/tests/analysis_tests/tests-reanalyze/termination/test.sh b/rescript-ecosystem/packages/core/compiler-source/tests/analysis_tests/tests-reanalyze/termination/test.sh
index 7c301befb..dbab638bc 100755
--- a/rescript-ecosystem/packages/core/compiler-source/tests/analysis_tests/tests-reanalyze/termination/test.sh
+++ b/rescript-ecosystem/packages/core/compiler-source/tests/analysis_tests/tests-reanalyze/termination/test.sh
@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 output="expected/termination.txt"
 dune exec rescript-tools -- reanalyze -config -ci -debug > $output
 # CI. We use LF, and the CI OCaml fork prints CRLF. Convert.
diff --git a/rescript-ecosystem/packages/core/compiler-source/tests/analysis_tests/tests/test.sh b/rescript-ecosystem/packages/core/compiler-source/tests/analysis_tests/tests/test.sh
index 993782b86..12fd9b5ae 100755
--- a/rescript-ecosystem/packages/core/compiler-source/tests/analysis_tests/tests/test.sh
+++ b/rescript-ecosystem/packages/core/compiler-source/tests/analysis_tests/tests/test.sh
@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 for file in src/*.{res,resi}; do
   output="$(dirname $file)/expected/$(basename $file).txt"
   ../../../_build/install/default/bin/rescript-editor-analysis test $file &> $output
diff --git a/rescript-ecosystem/packages/core/compiler-source/tests/tools_tests/test.sh b/rescript-ecosystem/packages/core/compiler-source/tests/tools_tests/test.sh
index 4e44f4217..d111ad3d5 100755
--- a/rescript-ecosystem/packages/core/compiler-source/tests/tools_tests/test.sh
+++ b/rescript-ecosystem/packages/core/compiler-source/tests/tools_tests/test.sh
@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 for file in src/*.{res,resi}; do
   output="$(dirname $file)/expected/$(basename $file).json"
   ../../_build/install/default/bin/rescript-tools doc $file > $output
diff --git a/rescript-ecosystem/rescript/tests/analysis_tests/tests-generic-jsx-transform/test.sh b/rescript-ecosystem/rescript/tests/analysis_tests/tests-generic-jsx-transform/test.sh
index c58c8e70b..9e049e22e 100755
--- a/rescript-ecosystem/rescript/tests/analysis_tests/tests-generic-jsx-transform/test.sh
+++ b/rescript-ecosystem/rescript/tests/analysis_tests/tests-generic-jsx-transform/test.sh
@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 for file in src/*.res; do
   output="$(dirname $file)/expected/$(basename $file).txt"
   ../../../_build/install/default/bin/rescript-editor-analysis test $file &> $output
diff --git a/rescript-ecosystem/rescript/tests/analysis_tests/tests-incremental-typechecking/test.sh b/rescript-ecosystem/rescript/tests/analysis_tests/tests-incremental-typechecking/test.sh
index c58c8e70b..9e049e22e 100755
--- a/rescript-ecosystem/rescript/tests/analysis_tests/tests-incremental-typechecking/test.sh
+++ b/rescript-ecosystem/rescript/tests/analysis_tests/tests-incremental-typechecking/test.sh
@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 for file in src/*.res; do
   output="$(dirname $file)/expected/$(basename $file).txt"
   ../../../_build/install/default/bin/rescript-editor-analysis test $file &> $output
diff --git a/rescript-ecosystem/rescript/tests/analysis_tests/tests-reanalyze/deadcode/test.sh b/rescript-ecosystem/rescript/tests/analysis_tests/tests-reanalyze/deadcode/test.sh
index a408b9da0..b1ad21c1b 100755
--- a/rescript-ecosystem/rescript/tests/analysis_tests/tests-reanalyze/deadcode/test.sh
+++ b/rescript-ecosystem/rescript/tests/analysis_tests/tests-reanalyze/deadcode/test.sh
@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 DEBUG_FLAG="-debug"
 
 if [ "$RUNNER_OS" == "Windows" ]; then
diff --git a/rescript-ecosystem/rescript/tests/analysis_tests/tests-reanalyze/termination/test.sh b/rescript-ecosystem/rescript/tests/analysis_tests/tests-reanalyze/termination/test.sh
index 7c301befb..dbab638bc 100755
--- a/rescript-ecosystem/rescript/tests/analysis_tests/tests-reanalyze/termination/test.sh
+++ b/rescript-ecosystem/rescript/tests/analysis_tests/tests-reanalyze/termination/test.sh
@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 output="expected/termination.txt"
 dune exec rescript-tools -- reanalyze -config -ci -debug > $output
 # CI. We use LF, and the CI OCaml fork prints CRLF. Convert.
diff --git a/rescript-ecosystem/rescript/tests/analysis_tests/tests/test.sh b/rescript-ecosystem/rescript/tests/analysis_tests/tests/test.sh
index 993782b86..12fd9b5ae 100755
--- a/rescript-ecosystem/rescript/tests/analysis_tests/tests/test.sh
+++ b/rescript-ecosystem/rescript/tests/analysis_tests/tests/test.sh
@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 for file in src/*.{res,resi}; do
   output="$(dirname $file)/expected/$(basename $file).txt"
   ../../../_build/install/default/bin/rescript-editor-analysis test $file &> $output
diff --git a/rescript-ecosystem/rescript/tests/tools_tests/test.sh b/rescript-ecosystem/rescript/tests/tools_tests/test.sh
index 4e44f4217..d111ad3d5 100755
--- a/rescript-ecosystem/rescript/tests/tools_tests/test.sh
+++ b/rescript-ecosystem/rescript/tests/tools_tests/test.sh
@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 for file in src/*.{res,resi}; do
   output="$(dirname $file)/expected/$(basename $file).json"
   ../../_build/install/default/bin/rescript-tools doc $file > $output