diff --git a/setup.sh b/setup.sh
index 0e989f1..26a151c 100755
--- a/setup.sh
+++ b/setup.sh
@@ -5,6 +5,8 @@ ERROR_SYSTEM_UNKNOWN='Unknown system found "%s".\n'
 ERROR_RUN_IN_EMPTY_DIRECTORY='Please run the script from an empty directory\n'
 ERROR_COULD_NOT_FIND_COMMAND='Could not find "%s", try installing it by running "%s".'
 
+MESSAGE_INSTALL_DEPENDENCY='Do you want to try and install this now? (y/N)? '
+
 # System Constants
 SYSTEM_NAME_LINUX='Linux'
 SYSTEM_NAME_MAC_OS='Darwin'
@@ -14,6 +16,7 @@ ALL_SYSTEM_SUPPORTED="${SYSTEM_NAME_LINUX} ${SYSTEM_NAME_MAC_OS} ${SYSTEM_NAME_F
 # Prerequisite constants.
 PREREQUISITE_CONSTANT_PREFIX='ALL_PREREQUISITE_'
 ALL_PREREQUISITE_GLOBAL='git php composer qrencode jq'
+ALL_PREREQUISITE_COMPOSER=$(curl -s https://raw.githubusercontent.com/bunq/sdk_php/master/composer.json | fgrep ext | tr -d "\"*\:,\ ")
 ALL_PREREQUISITE_LINUX=''
 ALL_PREREQUISITE_DARWIN='brew'
 ALL_PREREQUISITE_FREEBSD=''
@@ -57,10 +60,27 @@ function assertAllPrerequisitePresent
     else
         echo -n "$(determineInstructionInstallationAllPrerequisiteMissing "${allPrerequisiteMissing}")"
 
-        exit 1
+        if [${1} ]; then
+            exit 1
+        else
+            assertAllPrerequisitePresent true
+        fi
     fi
 }
 
+function assertComposerPrerequisitePresent
+{
+    phpModules=$(php -m)
+
+    for composerPrerequisite in ${ALL_PREREQUISITE_COMPOSER}; do
+        composerPrerequisite=${composerPrerequisite:4}
+
+        if [[ ${phpModules} != *"${composerPrerequisite}"* ]]; then
+            determineInstructionInstallation "php-${composerPrerequisite}" "$(determineSystemName)" "php-${composerPrerequisite}"
+        fi
+    done
+}
+
 function determineAllPrerequisiteMissing
 {
   for prerequisite in $(determineAllPrerequisite); do
@@ -129,7 +149,17 @@ function determineInstructionInstallation
     systemName="${2}"
     programPackageName=${3:-${programName}}
     commandInstallationConstantName="${COMMAND_INSTALLATION_PREFIX}$(capitalize ${systemName})"
-    printf "${ERROR_COULD_NOT_FIND_COMMAND}" "${programName}" "${!commandInstallationConstantName} ${programPackageName}"
+
+    warningMessage=$(printf "${ERROR_COULD_NOT_FIND_COMMAND}" "${programName}" "${!commandInstallationConstantName} ${programPackageName}")
+
+    echo ${warningMessage} >$(tty)
+    echo ${MESSAGE_INSTALL_DEPENDENCY} >$(tty)
+
+    read answer
+    if [ "$answer" != "${answer#[Yy]}" ] ;then
+        echo "${!commandInstallationConstantName} ${programPackageName} -y" >$(tty)
+        eval "${!commandInstallationConstantName} ${programPackageName} -y" >$(tty)
+    fi
 }
 
 function determineSystemName
@@ -176,6 +206,7 @@ function capitalizeFirstLetter
 assertIsSystemSupported
 assertIsRanInEmptyDirectory
 assertAllPrerequisitePresent
+assertComposerPrerequisitePresent
 cloneTinkerPhp
 composerInstall
 startTinker