diff --git a/src/__tests__/config.js b/src/__tests__/config.js
index 7fdb1e00..739e081a 100644
--- a/src/__tests__/config.js
+++ b/src/__tests__/config.js
@@ -54,6 +54,17 @@ describe('configuration API', () => {
 
       expect(getConfig().reactStrictMode).toBe(true)
     })
+
+    test('configure without reactStrictMode preserves the existing value', () => {
+      configure({reactStrictMode: true})
+      configure({testIdAttribute: 'not-data-testid'})
+
+      expect(getConfig().reactStrictMode).toBe(true)
+
+      configure({reactStrictMode: false})
+
+      expect(getConfig().reactStrictMode).toBe(false)
+    })
   })
 
   test('configure can set DTL and RTL options at once', () => {
diff --git a/src/config.js b/src/config.js
index dc8a5035..0b038e7d 100644
--- a/src/config.js
+++ b/src/config.js
@@ -27,7 +27,9 @@ function configure(newConfig) {
 
   configForRTL = {
     ...configForRTL,
-    reactStrictMode,
+    // Only overwrite the existing value when a new one is provided,
+    // so calling configure() for other options keeps reactStrictMode.
+    reactStrictMode: reactStrictMode ?? configForRTL.reactStrictMode,
   }
 }