Lower band chorus waves play an important role in the dynamics of energetic electrons in near-Earth space. The angle between wave vector and background magnetic field, known as the wave normal angle, strongly influences how they interact with electrons. In this study, we use observations from NASA’s Van Allen Probes to show two events where both the wave normal angle and amplitude of lower band chorus waves are influenced by small-scale fluctuations in background plasma density. These density fluctuations have spatial scales comparable to the wavelength of the chorus waves—just a few kilometers. We find that chorus waves tend to be nearly parallel to the magnetic field in high-density regions, and become very oblique in low-density regions. The very oblique waves observed in low-density regions cannot be explained by the usual generation mechanism involving anisotropic electrons. Instead, we use one-dimensional wave modeling to show that these oblique waves result from scattering of the initially quasi-parallel waves by the density irregularities.