diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/DartClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/DartClientCodegen.java
index f1f9016517d..ce6c6234c38 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/DartClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/DartClientCodegen.java
@@ -558,6 +558,18 @@ public class DartClientCodegen extends DefaultCodegen {
                 }
             }
         }
+        for (CodegenParameter p : op.allParams) {
+            if (p.isContainer) {
+                final String type = p.isArray ? "array" : "map";
+                if (typeMapping().containsKey(type)) {
+                    final String value = typeMapping().get(type);
+                    // Also add container imports for parameters.
+                    if (needToImport(value)) {
+                        op.imports.add(value);
+                    }
+                }
+            }
+        }
         return op;
     }
 
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/DartDioClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/DartDioClientCodegen.java
index 68b66580e8a..3f1b69ad669 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/DartDioClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/DartDioClientCodegen.java
@@ -327,7 +327,7 @@ public class DartDioClientCodegen extends DartClientCodegen {
             Set<String> imports = new HashSet<>();
             for (String item : op.imports) {
                 if (needToImport(item)) {
-                    if (importMapping().containsKey(item) && needToImport(item)) {
+                    if (importMapping().containsKey(item)) {
                         fullImports.add(importMapping().get(item));
                     } else {
                         imports.add(underscore(item));