diff --git a/README.md b/README.md
index 6d2d55b..ff1761f 100644
--- a/README.md
+++ b/README.md
@@ -19,7 +19,7 @@ cargo install pwasm-utils-cli --bin wasm-prune
 wasm-prune <input_wasm_binary.wasm> <output_wasm_binary.wasm>
 ```
 
-This will optimize WASM symbols tree to leave only those elements that are used by contract `_call` function entry.
+This will optimize WASM symbols tree to leave only those elements that are used by contract `call` function entry.
 
 ## Gas counter (wasm-gas)
 
diff --git a/cli/prune/main.rs b/cli/prune/main.rs
index 658e249..50d40d5 100644
--- a/cli/prune/main.rs
+++ b/cli/prune/main.rs
@@ -8,7 +8,7 @@ use clap::{App, Arg};
 fn main() {
     logger::init_log();
 
-    let matches = App::new("wasm-opt")
+    let matches = App::new("wasm-prune")
                         .arg(Arg::with_name("input")
                             .index(1)
                             .required(true)
@@ -22,12 +22,12 @@ fn main() {
                             .short("e")
                             .takes_value(true)
                             .value_name("functions")
-                            .help("Comma-separated list of exported functions to keep. Default: _call"))
+                            .help(&format!("Comma-separated list of exported functions to keep. Default: '{}'", utils::CALL_SYMBOL)))
                         .get_matches();
 
     let exports = matches
                     .value_of("exports")
-                    .unwrap_or("_call")
+                    .unwrap_or(utils::CALL_SYMBOL)
                     .split(',')
                     .collect();
 
@@ -39,7 +39,7 @@ fn main() {
     // Invoke optimizer
     //   Contract is supposed to have only these functions as public api
     //   All other symbols not usable by this list is optimized away
-    utils::optimize(&mut module, exports).expect("Optimizer to finish without errors");
+    utils::optimize(&mut module, exports).expect("Optimizer failed");
 
-    parity_wasm::serialize_to_file(&output, module).unwrap();
+    parity_wasm::serialize_to_file(&output, module).expect("Serialization failed");
 }
diff --git a/src/pack.rs b/src/pack.rs
index e8a1096..85d4c2b 100644
--- a/src/pack.rs
+++ b/src/pack.rs
@@ -33,15 +33,15 @@ impl fmt::Display for Error {
             Error::NoTypeSection => write!(f, "No type section in the module"),
             Error::NoExportSection => write!(f, "No export section in the module"),
             Error::NoCodeSection => write!(f, "No code section inthe module"),
-            Error::InvalidCreateSignature => write!(f, "Exported symbol `deploy` has invalid signature, should be () -> ()"),
-            Error::InvalidCreateMember => write!(f, "Exported symbol `deploy` should be a function"),
-            Error::NoCreateSymbol => write!(f, "No exported `deploy` symbol"),
+            Error::InvalidCreateSignature => write!(f, "Exported symbol `{}` has invalid signature, should be () -> ()", CREATE_SYMBOL),
+            Error::InvalidCreateMember => write!(f, "Exported symbol `{}` should be a function", CREATE_SYMBOL),
+            Error::NoCreateSymbol => write!(f, "No exported `{}` symbol", CREATE_SYMBOL),
             Error::NoImportSection => write!(f, "No import section in the module"),
         }
     }
 }
 
-/// If module has an exported "_create" function we want to pack it into "constructor".
+/// If module has an exported "CREATE_SYMBOL" function we want to pack it into "constructor".
 /// `raw_module` is the actual contract code
 /// `ctor_module` is the constructor which should return `raw_module`
 pub fn pack_instance(raw_module: Vec<u8>, mut ctor_module: elements::Module) -> Result<elements::Module, Error> {
@@ -49,7 +49,7 @@ pub fn pack_instance(raw_module: Vec<u8>, mut ctor_module: elements::Module) ->
     // Total number of constructor module import functions
     let ctor_import_functions = ctor_module.import_section().map(|x| x.functions()).unwrap_or(0);
 
-    // We need to find an internal ID of function witch is exported as "_create"
+    // We need to find an internal ID of function witch is exported as "CREATE_SYMBOL"
     // in order to find it in the Code section of the module
     let mut create_func_id = {
         let found_entry = ctor_module.export_section().ok_or(Error::NoExportSection)?.entries().iter()
@@ -63,7 +63,7 @@ pub fn pack_instance(raw_module: Vec<u8>, mut ctor_module: elements::Module) ->
         // Calculates a function index within module's function section
         let function_internal_index = function_index - ctor_import_functions;
 
-        // Constructor should be of signature `func(i32)` (void), fail otherwise
+        // Constructor should be of signature `func()` (void), fail otherwise
         let type_id = ctor_module.function_section().ok_or(Error::NoCodeSection)?
             .entries().get(function_index - ctor_import_functions).ok_or(Error::MalformedModule)?
             .type_ref();
@@ -207,7 +207,7 @@ pub fn pack_instance(raw_module: Vec<u8>, mut ctor_module: elements::Module) ->
             &mut Section::Export(ref mut export_section) => {
                 for entry in export_section.entries_mut().iter_mut() {
                     if CREATE_SYMBOL == entry.field() {
-                        // change _create export name into default _call
+                        // change "CREATE_SYMBOL" export name into default "CALL_SYMBOL"
                         *entry.field_mut() = CALL_SYMBOL.to_owned();
                         *entry.internal_mut() = elements::Internal::Function(last_function_index as u32);
                     }