diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9c8c41c4..cf1fb251 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,9 @@
 ## Version 1.2 (in progress)
 
+
+* `set_default_str` now only sets string, and `set_default_val` will evaluate the default string given [#26](https://github.com/CLIUtils/CLI11/issues/26)
 * Required positionals now take priority over subcommands [#23](https://github.com/CLIUtils/CLI11/issues/23)
+* Extra requirements enforced by Travis
 
 ## Version 1.1
 
diff --git a/include/CLI/App.hpp b/include/CLI/App.hpp
index cedef560..cdb91abc 100644
--- a/include/CLI/App.hpp
+++ b/include/CLI/App.hpp
@@ -261,7 +261,7 @@ class App {
         if(defaulted) {
             std::stringstream out;
             out << variable;
-            opt->set_default_val(out.str());
+            opt->set_default_str(out.str());
         }
         return opt;
     }
@@ -307,7 +307,7 @@ class App {
         Option *opt = add_option(name, fun, description, defaulted);
         opt->set_custom_option(detail::type_name<T>(), -1, true);
         if(defaulted)
-            opt->set_default_val("[" + detail::join(variable) + "]");
+            opt->set_default_str("[" + detail::join(variable) + "]");
         return opt;
     }
 
@@ -410,7 +410,7 @@ class App {
         if(defaulted) {
             std::stringstream out;
             out << member;
-            opt->set_default_val(out.str());
+            opt->set_default_str(out.str());
         }
         return opt;
     }
@@ -473,7 +473,7 @@ class App {
         typeval += " in {" + detail::join(options) + "}";
         opt->set_custom_option(typeval);
         if(defaulted) {
-            opt->set_default_val(member);
+            opt->set_default_str(member);
         }
         return opt;
     }
@@ -500,7 +500,7 @@ class App {
         if(defaulted) {
             std::stringstream out;
             out << variable;
-            opt->set_default_val(out.str());
+            opt->set_default_str(out.str());
         }
         return opt;
     }
diff --git a/include/CLI/Option.hpp b/include/CLI/Option.hpp
index 7dbe40d1..2c01a665 100644
--- a/include/CLI/Option.hpp
+++ b/include/CLI/Option.hpp
@@ -431,7 +431,16 @@ class Option {
     }
 
     /// Set the default value string representation
-    void set_default_val(std::string val) { defaultval_ = val; }
+    void set_default_str(std::string val) { defaultval_ = val; }
+
+    /// Set the default value string representation and evaluate
+    void set_default_val(std::string val) {
+        set_default_str(val);
+        auto old_results = results_;
+        results_ = {val};
+        run_callback();
+        results_ = std::move(old_results);
+    }
 
     /// Set the type name displayed on this option
     void set_type_name(std::string val) { typeval_ = val; }
diff --git a/tests/HelpTest.cpp b/tests/HelpTest.cpp
index 863f4225..a1ad292d 100644
--- a/tests/HelpTest.cpp
+++ b/tests/HelpTest.cpp
@@ -194,16 +194,22 @@ TEST(THelp, ManualSetters) {
 
     CLI::App app{"My prog"};
 
-    int x;
+    int x = 1;
 
     CLI::Option *op1 = app.add_option("--op", x);
-    op1->set_default_val("12");
+    op1->set_default_str("12");
     op1->set_type_name("BIGGLES");
+    EXPECT_EQ(x, 1);
 
     std::string help = app.help();
 
     EXPECT_THAT(help, HasSubstr("=12"));
     EXPECT_THAT(help, HasSubstr("BIGGLES"));
+
+    op1->set_default_val("14");
+    EXPECT_EQ(x, 14);
+    help = app.help();
+    EXPECT_THAT(help, HasSubstr("=14"));
 }
 
 TEST(THelp, Subcom) {
diff --git a/tests/NewParseTest.cpp b/tests/NewParseTest.cpp
index 07042a5d..01c656d4 100644
--- a/tests/NewParseTest.cpp
+++ b/tests/NewParseTest.cpp
@@ -23,7 +23,7 @@ add_option(CLI::App &app, std::string name, cx &variable, std::string descriptio
     if(defaulted) {
         std::stringstream out;
         out << variable;
-        opt->set_default_val(out.str());
+        opt->set_default_str(out.str());
     }
     return opt;
 }