diff --git a/scripts/source_development_defaults.sh b/scripts/source_development_defaults.sh
index 34161eaa9..5975074e3 100644
--- a/scripts/source_development_defaults.sh
+++ b/scripts/source_development_defaults.sh
@@ -1,21 +1,31 @@
 #!/usr/bin/env bash
 
 if [[ "$OSTYPE" == 'linux'* ]]; then
   export MYSQL_UNIX_PORT="${XDG_RUNTIME_DIR:-/run/user/$UID}/mysql.sock"
   export ANDROID_HOME="${ANDROID_HOME:-$HOME/Android/Sdk}"
 fi
 
 if [[ "$OSTYPE" == 'darwin'* ]]; then
   MARIADB_DIR="${XDG_DATA_HOME:-$HOME/.local/share}/MariaDB"
   export MYSQL_UNIX_PORT="$MARIADB_DIR"/mysql.sock
   export ANDROID_HOME="${ANDROID_HOME:-$HOME/Library/Android/sdk}"
 fi
 
 export PATH="$PATH":"$ANDROID_HOME"/emulator:"$ANDROID_HOME"/tools
 export PATH="$PATH":"$ANDROID_HOME"/tools/bin:"$ANDROID_HOME"/platform-tools
 
 # ANDROID_SDK_ROOT is deprecated, but it's still used by some tooling
 # such as sdkmanager. ANDROID_HOME is the new prefered env var.
 export ANDROID_SDK_ROOT="${ANDROID_SDK_ROOT:-$ANDROID_HOME}"
 
 export PATH="$PATH":./node_modules/.bin
+
+# mysql2 package wants stable prefixes for temporary directory paths
+# 'nix develop' will set TMP and related variables to something different each
+# invocation
+export TMP=/tmp/app.comm
+export TEMP="$TMP"
+export TMPDIR="$TMP"
+export TEMPDIR="$TMP"
+
+mkdir -p "$TMP"