diff --git a/strops.c b/strops.c
index 7ba6b9f..c1ff2f6 100644
--- a/strops.c
+++ b/strops.c
@@ -185,10 +185,21 @@ char* strops_remove_at_pos_char(const char* string, ull_t pos) {
     return result;
 }
 
+void strops_remove_at_pos_char_inplace(char* string, ull_t pos) {
+    assert(pos <= strops_length(string) && "pos needs to be inside string");
+    ull_t length = strops_length(string);
+    string[pos] = 0;
+    ull_t i;
+    for (i = pos; i < length; i++) {
+        string[i] = string[i + 1];
+    }
+}
+
 char* strops_trim_right_whitespace(const char* string) {
     char* result = strops_copy(string);
+    char* tmp;
     while (strops_contains_char("\t\n\v\f\r ", result[strops_length(result) - 1])) {
-        result = strops_remove_at_pos_char(result, strops_length(result) - 1);
+        strops_remove_at_pos_char_inplace(result, strops_length(result) - 1);
     }
     result = realloc(result, strops_length(result));
     return result;
@@ -197,7 +208,7 @@ char* strops_trim_right_whitespace(const char* string) {
 char* strops_trim_left_whitespace(const char* string) {
     char* result = strops_copy(string);
     while (strops_contains_char("\t\n\v\f\r ", result[0])) {
-        result = strops_remove_at_pos_char(result, 0);
+        strops_remove_at_pos_char_inplace(result, 0);
     }
     result = realloc(result, strops_length(result));
     return result;
@@ -215,7 +226,7 @@ char* strops_trim_both_whitespace(const char* string) {
 char* strops_trim_right_chars(const char* string, const char* chars_to_remove) {
     char* result = strops_copy(string);
     while (strops_contains_char(chars_to_remove, result[strops_length(result) - 1])) {
-        result = strops_remove_at_pos_char(result, strops_length(result) - 1);
+        strops_remove_at_pos_char_inplace(result, strops_length(result) - 1);
     }
     result = realloc(result, strops_length(result));
     return result;
@@ -224,7 +235,7 @@ char* strops_trim_right_chars(const char* string, const char* chars_to_remove) {
 char* strops_trim_left_chars(const char* string, const char* chars_to_remove) {
     char* result = strops_copy(string);
     while (strops_contains_char(chars_to_remove, result[0])) {
-        result = strops_remove_at_pos_char(result, 0);
+        strops_remove_at_pos_char_inplace(result, 0);
     }
     result = realloc(result, strops_length(result));
     return result;
@@ -248,7 +259,7 @@ char* strops_trim_right_string(const char* string, const char* string_to_remove)
     while (strcmp(tmp, string_to_remove) == 0) {
         ull_t i;
         for (i = 0; i < strops_length(string_to_remove); i++) {
-            result = strops_remove_at_pos_char(result, offset);
+            strops_remove_at_pos_char_inplace(result, offset);
         }
         offset = strops_length(result) - strops_length(string_to_remove);
         tmp = result + offset;
@@ -265,7 +276,7 @@ char* strops_trim_left_string(const char* string, const char* string_to_remove)
     while (strcmp(tmp, string_to_remove) == 0) {
         ull_t i;
         for (i = 0; i < strops_length(string_to_remove); i++) {
-            result  = strops_remove_at_pos_char(result, 0);
+            strops_remove_at_pos_char_inplace(result, 0);
         }
         tmp = strops_copy_amount(result, strops_length(string_to_remove));
     }
@@ -289,7 +300,7 @@ char* strops_remove_chars(const char* string, const char* chars_to_remove) {
     ull_t i, j;
     for (i = 0; i < strops_length(chars_to_remove); i++) {
         while (strops_contains_char(result, chars_to_remove[i])) {
-            result = strops_remove_at_pos_char(result, strops_first_pos_of_char(result, chars_to_remove[i]));
+            strops_remove_at_pos_char_inplace(result, strops_first_pos_of_char(result, chars_to_remove[i]));
         }
     }
     result = realloc(result, strops_length(result));
@@ -304,7 +315,7 @@ char* strops_remove_string(const char* string, const char* string_to_remove) {
         ull_t offset = strops_first_pos_of_string(result, string_to_remove);
         ull_t i;
         for (i = 0; i < strops_length(string_to_remove); i++) {
-            result  = strops_remove_at_pos_char(result, offset);
+            strops_remove_at_pos_char_inplace(result, offset);
         }
     }
     result = realloc(result, strops_length(result));
diff --git a/strops.h b/strops.h
index fe33219..61b070f 100644
--- a/strops.h
+++ b/strops.h
@@ -4,10 +4,8 @@
 #include <stddef.h>
 
 /*
-    ATTENTION! THIS LIBRARY CURRENTLY LEAKS MEMORY!
     Functions that return char*, return a new heap-allocated string.
     The user of this library is responsible for freeing the memory of the result.
-    No function modifies the input string. The input string is copied at the beginning of a function.
     Only 7-Bit Ascii is supported.
 */
 
@@ -23,6 +21,7 @@ int strops_is_uppercase(const char* string);
 
 char* strops_insert_at_pos_string(const char* string, const char* string_to_insert, ull_t pos);
 char* strops_remove_at_pos_char(const char* string, ull_t pos);
+void strops_remove_at_pos_char_inplace(char* string, ull_t pos);
 
 char* strops_trim_right_whitespace(const char* string);
 char* strops_trim_left_whitespace(const char* string);