diff --git a/Dapper/DynamicParameters.cs b/Dapper/DynamicParameters.cs
index 34f0848d9..c2c82de0f 100644
--- a/Dapper/DynamicParameters.cs
+++ b/Dapper/DynamicParameters.cs
@@ -228,14 +228,20 @@ protected void AddParameters(IDbCommand command, SqlMapper.Identity identity)
                 outputCallbacks?.ForEach(generator => generator());
             }
 
-            foreach (var param in parameters.Values)
-            {
-                if (param.CameFromTemplate) continue;
-
-                var dbType = param.DbType;
-                var val = param.Value;
-                string name = Clean(param.Name);
-                var isCustomQueryParameter = val is SqlMapper.ICustomQueryParameter;
+            foreach (var param in parameters.Values)
+            {
+                if (param.CameFromTemplate) continue;
+
+                var dbType = param.DbType;
+                var val = param.Value;
+                string name = Clean(param.Name);
+                if (RemoveUnused && identity.CommandType.GetValueOrDefault(CommandType.Text) == CommandType.Text
+                    && (!SqlMapper.Settings.SupportLegacyParameterTokens || !CompiledRegex.LegacyParameter.IsMatch(command.CommandText))
+                    && !SqlMapper.IsParameterUsed(command.CommandText, name))
+                {
+                    continue;
+                }
+                var isCustomQueryParameter = val is SqlMapper.ICustomQueryParameter;
 
                 SqlMapper.ITypeHandler? handler = null;
                 if (dbType is null && val is not null && !isCustomQueryParameter)
diff --git a/Dapper/SqlMapper.cs b/Dapper/SqlMapper.cs
index 8f3956cab..262c5d721 100644
--- a/Dapper/SqlMapper.cs
+++ b/Dapper/SqlMapper.cs
@@ -2411,16 +2411,19 @@ public static object SanitizeParameterValue(object? value)
             return value;
         }
 
-        private static IEnumerable<PropertyInfo> FilterParameters(IEnumerable<PropertyInfo> parameters, string sql)
-        {
-            var list = new List<PropertyInfo>(16);
-            foreach (var p in parameters)
-            {
-                if (Regex.IsMatch(sql, @"[?@:$]" + p.Name + @"([^\p{L}\p{N}_]+|$)", RegexOptions.IgnoreCase | RegexOptions.Multiline | RegexOptions.CultureInvariant))
-                    list.Add(p);
-            }
-            return list;
-        }
+        private static IEnumerable<PropertyInfo> FilterParameters(IEnumerable<PropertyInfo> parameters, string sql)
+        {
+            var list = new List<PropertyInfo>(16);
+            foreach (var p in parameters)
+            {
+                if (IsParameterUsed(sql, p.Name))
+                    list.Add(p);
+            }
+            return list;
+        }
+
+        internal static bool IsParameterUsed(string sql, string name)
+            => Regex.IsMatch(sql, @"[?@:$]" + Regex.Escape(name) + @"([^\p{L}\p{N}_]+|$)", RegexOptions.IgnoreCase | RegexOptions.Multiline | RegexOptions.CultureInvariant);
 
         /// <summary>
         /// Replace all literal tokens with their text form.
diff --git a/Directory.Packages.props b/Directory.Packages.props
index 2f91a3cca..8f2772419 100644
--- a/Directory.Packages.props
+++ b/Directory.Packages.props
@@ -35,6 +35,7 @@
     <PackageVersion Include="Norm.net" Version="5.4.0" />
     <PackageVersion Include="Npgsql" Version="10.0.2" />
     <PackageVersion Include="PetaPoco" Version="5.1.306" />
+    <PackageVersion Include="pengdows.crud.fakeDb" Version="2.0.5" />
     <PackageVersion Include="RepoDb.SqlServer" Version="1.13.1" />
     <PackageVersion Include="ServiceStack.OrmLite.SqlServer" Version="10.0.6" />
     <PackageVersion Include="Snowflake.Data" Version="5.5.0" />
diff --git a/tests/Dapper.Tests/Dapper.Tests.csproj b/tests/Dapper.Tests/Dapper.Tests.csproj
index 93b498618..09947a89a 100644
--- a/tests/Dapper.Tests/Dapper.Tests.csproj
+++ b/tests/Dapper.Tests/Dapper.Tests.csproj
@@ -31,8 +31,9 @@
     <PackageReference Include="log4net" />
   </ItemGroup>
 
-  <ItemGroup Condition="'$(TargetFramework)' != 'net481'">
-    <PackageReference Include="Npgsql" />
+  <ItemGroup Condition="'$(TargetFramework)' != 'net481'">
+    <PackageReference Include="pengdows.crud.fakeDb" />
+    <PackageReference Include="Npgsql" />
     <PackageReference Include="Snowflake.Data" />
   </ItemGroup>
 
diff --git a/tests/Dapper.Tests/FakeDbTests.Issue1241.cs b/tests/Dapper.Tests/FakeDbTests.Issue1241.cs
new file mode 100644
index 000000000..aa0f329a0
--- /dev/null
+++ b/tests/Dapper.Tests/FakeDbTests.Issue1241.cs
@@ -0,0 +1,30 @@
+#if !NET481
+using System.Collections.Generic;
+using System.Linq;
+using pengdows.crud.fakeDb;
+using Xunit;
+
+namespace Dapper.Tests
+{
+    public sealed class FakeDbIssue1241Tests
+    {
+        [Fact]
+        public void RemoveUnusedSkipsExplicitlyAddedCollectionParameters()
+        {
+            using var conn = new fakeDbConnection(new FakeDataStore());
+            conn.EnqueueNonQueryResult(1);
+            conn.Open();
+
+            var parameters = new DynamicParameters();
+            parameters.Add("ids", new[] { 1, 2, 3 });
+            parameters.Add("used", 42);
+
+            conn.Execute("select 1 where Value = @used", parameters);
+
+            var command = conn.LastCreatedCommand!;
+            Assert.DoesNotContain(command.Parameters.Cast<System.Data.IDataParameter>(),
+                p => p.ParameterName.StartsWith("ids", System.StringComparison.OrdinalIgnoreCase));
+        }
+    }
+}
+#endif